Typically timber such as beams, planks or planks comes in a specific size, but often construction requires materials that are longer, wider or thicker. Therefore, to obtain the required dimensions, there are different kinds connections using cuts, which are made manually by marking or with special equipment.

Width connections

When joining narrow boards, boards of the required size are obtained.

There are several ways to connect.

1) Connection to a smooth joint;
With this method of connection, each strip or board is called a plot, and the seam that is formed as a result of the connection is called a joint. The quality of the jointing is indicated by the absence of gaps between the edges of adjacent plots.
2) Rail connection;
Along the edges of the plots, grooves are selected and inserted into their slats, fastening the plots to each other. The thickness of the strip and the width of the groove should not exceed 1/3 of the thickness of the board.
3) Connection in a quarter;
In the plots to be fastened, they are selected along the entire length of the quarter. In this case, the size of the quarter, as a rule, does not exceed half the thickness of the plot.
3) Connection in a groove and a ridge (rectangular and triangular);
This type of connection provides the plot with a groove on one side and a ridge on the other. The comb can be either rectangular or triangular, but the latter is rarely used because its strength is slightly poorer. Groove and tongue joints are quite popular and often used by parquet manufacturers. The disadvantage of such a connection is considered to be less profitability, since more boards are used.
4) Connection " dovetail»;

This type of attachment is a bit similar to the previous one, only the comb has a trapezoidal shape. Well, hence the name.

Also, when assembling shields, dowels, lugs in the groove and a ridge are used with the laths glued into the end. Among the glued strips, there are triangular, rectangular and glued ones, and when using dowels, the dovetail groove is mainly chosen. All this is needed to securely fasten the shield.

Length splice

Among the popular types of connection along the length can be distinguished: end-to-end, on "mustache", in a groove and a comb, on a serrated adhesive connection, in a quarter and on a rail. The most popular is the toothed joint because it has the best strength.

There is also splicing, when longer segments are joined together. This can happen in several ways. For example, half-wood, oblique cut, oblique and straight overhead lock, oblique and straight tension lock and end-to-end. When choosing a splicing in a half-tree, the required length of the joint should be 2 or 2.5 times the thickness of the timber. For greater reliability, a dowel is used, for example, this can be found in the construction of block houses.

When using an oblique cut with an end trimming, the dimensions are 2.5 - 3 of the thickness of the bar and is also attached with dowels.

The connection with a straight or oblique overhead lock is used in structures in which tensile forces are present. A straight surface-mounted lock is located on the support, and an oblique one can be placed at the supports.

If you decide to use an oblique notch with an end cut, then the connection should have 2.5 or 3 bar thicknesses. In this case, the same dowel is used.

When joining with a straight or oblique tension lock, you do not have to worry about strength, but such a connection has difficulties in manufacturing, and when the wood dries out, the wedges are weakened, so this method of connection is not suitable for serious structures.

Butt-splicing is when two ends of a bar are placed on a support and stapled securely together.

The connection of beams or logs can be found during the construction of walls or in the upper or lower strapping in frame houses... The main types of connections include half-wood, half-leg, spike and corner frying pan.
A cut in half a tree is considered to be cutting or cutting of half the thickness at the ends of the beams, after which they are connected at an angle of 90 degrees.

The half-leg connection is formed when cutting at the ends of the beams of inclined planes, due to which the beams are tightly connected. The size of the slope is determined by the formula.
Cutting with a corner frying pan is very similar to cutting in half a tree, but hallmark is that with such a connection, one of the bars loses a small part in width.

Height connection

The cross-shaped connection of the beams can be found during the construction of the bridge. With this method, you can use a half-wood connection, a third and a quarter of a tree, or a notch of one bar.

Build-up

Build-up of beams and logs is called the connection of elements in height, which is often used in the construction of poles or a match.

There are several types of building:

1) end-to-end with a secret spike;
2) end-to-end with a through ridge;
3) half-wood with bolt fastening;
4) half-wood with fastening with clamps;
5) half-wood with steel strip fastening;
6) an oblique cut with fastening with clamps;
7) back to back with overlays;
8) bolting;

The length of the joints is usually 2-3 times the thickness of the jointed beams or 2-3 times the diameter of the logs.

Spike connection

When spike-knitting bars, one makes a spike cut, and on the other an eyelet or a nest. Spike-knit bars are often used to create joinery, doors, windows or transoms. All connections are made with glue. You can use not only one, but also two or more pins. The more tenons, the larger the bonding area. This type of connection can be divided into corner end, corner center and corner box.

With an angled end connection, an open through thorn is used (one, two or three), a thorn with a dark through and blind, plug-in dowels. Corner center joints can be found on doors. Corner center and end can additionally use nails, screws, dowels or bolts.

Well, that's probably all about the types of connections. This does not include nails, screws or bolts. Pure wood and a little bit of glue. :)

Connections of wooden elements have the task of connecting mating Construction Materials, for example edged beams so that they do not move relative to each other. According to the position and direction of the connected wooden elements, longitudinal joints and corner joints are distinguished, as well as joints at branches and crossings. Spatial connecting elements made of steel sheet and pre-drilled sheet steel cover plates often replace carpentry joints.

Joints that must transmit forces of a certain magnitude and direction, for example compressive forces, are also called joints of the connected wooden elements as rods, for example, compressed rods. Compressed rods connected under acute angle, can be connected to the cuttings. Other joints of wooden structures are made by joining wooden elements using connecting means.

By the type of connecting means, such connections are called nail or bolted, dowel or dowel connections. Glued wood is also used in wood construction. building construction... As they have particular advantages, the use of glued timber structures is of increasing importance.

Longitudinal connections

There are longitudinal connections on supports and longitudinal connections in the span. Above the supports, perpendicular pins are used, a joint "in a paw" and a partially trunnion joint "in a paw" (Fig. 1). To reinforce these joints, flat or round steel construction brackets can be driven in from the top or from the side. Often, wooden elements are joined to the forehead and secured only with construction brackets. If, however, large tensile forces act at the joint, for example at the girders on the roof rafters, then both elements are joined head-on on the support and are connected by side planks or perforated strips of corrosion-protected steel.

Rice. 1. Longitudinal connections

The runs can also be made in the form cantilever-suspended(Gerber runs) or articulated girders... They have a joint located in the place determined by the calculation, not far from the support, in which the bending moments are equal to zero and where there are no bending forces (Fig. 2). There the purlins are connected with a straight or oblique overlay. The incoming girder is held in place by a screw bolt, also called a hinge bolt. The hinge bolt with washers must take the load from the suspended purlin.

Rice. 2. Longitudinal connections of Gerber girders

Gerber runs with a joint lying on top are impractical, since there is a danger that the runs at the edge of the joint will come off. When the joint is suspended, spitting, there is no danger of separation.

To connect Gerber girders, spatial elements made of steel sheet are also used, which are also called Gerber connecting elements. They are attached with nails along the frontal abutting ends of the purlins (see Fig. 2).

Corner connections

Corner joints are necessary when two logs or beams in a corner are joined at a right or approximately right angle in the same plane. The most commonly used types of joints are notched trunnions, smooth angled foot, and compressed foot (Fig. 3). With the help of cut pins and smooth corner legs, the ends of the thresholds, girders and rafter legs lying on the supports or protruding cantilevered are connected. Nails or screw bolts can be used to secure the connections. The compressed paw has planes obliquely entering each other. It is especially suitable for joining loaded sills that lie completely on a support.

Rice. 3. Corner connections

Branches

When branching off, a bar suitable at a right or oblique angle in most cases superficially butts with another bar. V usual cases use a joint on the trunnions, and in secondary structures also a joint "in the paw". In addition, timber beams can be joined using metal connecting spatial elements. In trunnion joints, the trunnion thickness is approximately one third of the bar thickness. The trunnions have a length in most cases from 4 to 5 cm. The groove for the trunnion is made 1 cm deeper so that the compression force is transmitted not through the section of the trunnion, but through a large area of ​​the remaining section of the beams.

When the trunnions are arranged, normal trunnions are distinguished, passing through the entire width of the beam, and protruding(hemp) pins, which are used for connections at the ends of the bars (Fig. 4). If the beams in the connection do not fit at right angles to each other, for example, at corner struts, then the trunnion at the brace must be made at right angles to the horizontal (or vertical) structural element (see Fig. 4).

Rice. 4. Connections with trunnions

When installing pins in wooden beams and the girders, the trunnion must carry the entire load. It is more advantageous to carry out such compounds using girder shoes made of corrosion-resistant steel (fig. 9). These shoes are secured with special nails in such a way as to prevent them from skewing and turning relative to the joint. In addition, the cross-section of the beam is not weakened by the trunnion holes.

Cross joins

Wooden beams can intersect in the same plane or with offset planes and be overhead or support. Bars intersecting in one plane can intersect "IN THE PAW" if the weakening of the section does not play any role (Fig. 5). It is advisable to tie the intersecting overhead thresholds on the support beams with round dowels (pins) made of solid wood or steel from 10 to 12 cm long (Fig. 6).

Rice. 5. Connection "in the paw"

Rice. 6. Connection with round keys (pins)

The bars joining on the side get good support on the post, if their connection is made "IN PAZ" (Fig. 7). For this, the planes of intersection of both elements are cut to a depth of 1.5 to 2.0 cm. In this case, a non-displaceable connection is obtained, which is fixed with a screw bolt.

Rice. 7. Groove connection

When joining inclined and horizontal beams, as is usually the case when joining rafter legs with girders - thresholds, a cut is made in the rafter leg corresponding to the slope, which is called inset(fig. 8).

Rice. 8. Inset of the rafter leg

The depth of the insert in the rafter legs at a normal section height of 16 to 20 cm is from 2.5 to 3.5 cm. For fastening, one nail is used, which penetrates the threshold for a length of at least 12 cm, or a special anchor for attaching the rafters to the girders.

Rice. 9. Steel shoe connection

Cuttings

In the case of notches, a compressed rod entering at an acute angle is connected to another bar by means of one or more force-transmitting planes on its frontal side. According to the number and position of the force-transmitting planes, a frontal cut, a cut with a tooth and a double frontal cut with a tooth are distinguished.

At frontal cut(also called a frontal stop) the receiving bar has a wedge-shaped notch that matches the shape of the end of the compressed rod (Fig. 10). The frontal plane should pass at an angle dividing the obtuse outer corner cuts in half. The fastening bolt must have the same direction, ensuring the joint against lateral displacement. To mark the cuts, parallels are drawn at the same distance from the sides of the corner, which must be halved. The connecting line between the point of their intersection and the apex of the obtuse angle will be the bisector of this angle (see Fig. 10). The position of the fastening bolt is obtained if the distance between the bisector and the end of the cut is divided into three parts parallel to the bisector (see Fig. 10).

Rice. 10. Frontal notch

Under the action of the compressive force, the wood lying in front of the frontal part of the compressed bar works on slice(see fig. 10). Since the permissible stress on a cut of wood along the grain is relatively small (0.9 MN / m 2), the plane of the wood in front of the cut edge (cut plane) should be large enough. Since, in addition, cracking due to shrinkage should be taken into account, then, with rare exceptions, the length of the cut plane should not be less than 20 cm.

At reverse or toothed groove the plane of the notch is cut at right angles to the underside of the compressed rod (fig. 11). Due to the fact that due to the eccentric connection in the toothed groove there can be a risk of splitting of the compressed rod, it is necessary that the free end of the groove does not fit snugly against the support rod and a seam is provided between them.

Rice. 11. Serrated notch

Double cut consists, as a rule, of a frontal cut in combination with a toothed cut (Fig. 12). The direction of the cutting planes is the same as for each of the cuttings of this combination. However, the toothed cut in this case must be at least 1 cm deeper in order for its cut plane to be below the cut plane of the frontal cut. The fastening bolt should run parallel to the frontal part of the notch approximately halfway between the bisector and the top of the sharp corner of the joint.

Rice. 12. Double cut

Cutting depth t v is limited according to DIN 1052. For this, the abutment angle (a) and the height h of the bar to be cut (Table 1) are decisive.

Pin and bolt connections

In the case of pin and bolt connections wooden beams or boards touching the sides are connected by cylindrical connecting elements, such as rod dowels, bolts with countersunk heads and nuts, ordinary bolts with nuts. These rod dowels and bolts must prevent the timber elements from sliding in the joint plane, also called the shear plane. In this case, forces act perpendicular to the axis of the rod dowel or bolt. The dowels and bolts work in bending at the same time. In the connected wooden elements all efforts are focused on inner surface holes for dowels or bolts.

The number of rod dowels and bolts installed at the junction depends on the magnitude of the transmitted force. In this case, as a rule, at least two such elements should be installed (Fig. 13).

Rice. 13. Connection with rod dowels

In one connection, many cut planes can be located next to each other. According to the number of cut planes, which are connected by the same connecting elements, single-shear, double-shear and multi-shear dowel and bolt connections are distinguished (Fig. 14). According to DIN 1052, one-shear bearing connections with rod dowels must have at least four rod dowels.

Rice. 14. Bolted connections

For bolted connections, bolts with nuts made of steel with a standard diameter of 12, 16, 20 and 24 mm are mainly used. To prevent the head and nut of the bolt from cutting into the wood, strong steel washers should be placed under them. Minimum dimensions of these washers are given for different bolt diameters in DIN 1052 (table 2).

To prevent splitting of the timber elements to be connected by rod dowels and bolts, these connecting means must be installed minimum distances between themselves, as well as from the loaded and unloaded ends. The minimum distances depend on the direction of force, on the direction of the grain of the wood and on the diameter of the dowel bar or bolt db and do (fig. 15 and 16). Bearing bolts with nuts must maintain greater distances between themselves and from the loaded end than in the case of rod dowels and bolts with hidden heads. On the other hand, rod dowels or bolts with hidden heads that are close to each other in the direction of the wood grain should be spaced apart relative to the cut line so that the joints do not crack (see Fig. 15).

Rice. 15. Minimum distances in the case of rod dowels and concealed head screws

Rice. 16. Minimum distances in the case of bearing bolts

Holes for pins and bolts are pre-drilled perpendicular to the shear plane. For this, electric drills with a parallel movement bed are used. For pins when drilling holes in wood and when drilling holes in wood and metal connectors at the same time, the hole diameter must match the diameter of the pin.

Also, the bolt holes should match the bolt diameter well. The hole diameter must not be increased by more than 1 mm compared to the bolt diameter. At bolted connections bad when the bolt sits loosely in the hole. It is also bad if, due to the shrinkage of the wood, the clamp of the bolt in the hole gradually weakens. In this case, a backlash occurs in the shear plane, which leads to even greater pressure of the bolt rod on the boundary planes of the walls of the holes (Fig. 17). Due to the associated flexibility, bolted connections cannot be applied indefinitely. For simple structures such as sheds and sheds, as well as forests, they can, however, be used. In any case, in the finished structure, the bolts must be tightened repeatedly during operation.

Rice. 17. Backlash when bolted

Dowel connections

Dowels are fasteners made of solid wood or metal, which are used together with bolts to connect smooth-joining wooden elements (Fig. 18). They are positioned in such a way that they act evenly on the surface of the elements to be joined. In this case, the transfer of forces is carried out only through the dowels, while the bolts provide a clamping effect in the connection so that the dowels cannot tip over. The laths made of flat or profile steel are also attached to the wooden elements using dowels. For this, use one-sided dowels or flat steel dowels. Dowels come in various shapes and types.

Rice. 18. Connection of wooden elements using dowels and bolts

When installing dowel joints with pressed-in dowels, first, holes for the bolts are drilled in the connected elements. Thereafter, the wooden elements are separated again and, if necessary, a groove is cut out for the main plate. Depending on the construction technology, the dowel is fully or partially driven into the groove of one of the connected elements using a mallet. For the final clamping of a precisely aligned connection, special clamping bolts with a large washer are used. Connections with many or large press-in dowels are clamped using hydraulic press... When connecting with a large number of dowels, as is the case when making corner joints in frames made of glued board elements, it is more preferable to use round plug-in dowels, since with pressed dowels the pressing pressure may be too high (Fig. 19).

Rice. 19. Dowel joint in the corner of the frame

Each dowel, as a rule, must correspond to one bolt with nut, the diameter of which depends on the size of the dowel (Table 3). The size of the washer is the same as for bolted connections. Larger or smaller dowels can be used depending on the strength of the force acting on the connection. The most common diameters are from 50 to 165 mm. In the drawings, the size of the dowels is indicated by symbols (Table 4).

Table 4. Drawing symbols for special dowels
Symbol	Dowel size
	from 40 to 55 mm
	from 56 to 70 mm
	from 71 to 85 mm
	from 86 to 100 mm
	Nominal dimensions> 100 mm

At placement of dowels you should adhere to certain distances of the dowels between themselves and from the edges of the wooden elements. These minimum distances according to DIN 1052 depend on the type of plug and on its diameter (see table 3).

Bolts with dowel nuts are almost always guided through the center of the dowel. Only for rectangular and flat steel dowels do they lie outside the plane of the dowel. When tightening the nuts on the bolts, the washers should cut about 1 mm into the wood. With dowel connections, the bolted nuts must be re-tightened a few months after installation, so that their tightening effect remains even after the wood has shrunk. They talk about a connection with a constant transmission of force.

Load bearing stud connections

Bearing dowel (nail) connections have the task of transmitting tensile and compressive forces. With the help of dowel joints, load-bearing parts can be fastened, for example, for freely supported trusses, as well as structures made of boards and beams. Stud connections can be made with single-shear, double-shear and multi-shear. In this case, the size of the nails should correspond to the thickness of the lumber and the depth of driving. In addition, when placing the nails, certain distances between them must be maintained. Holes in bearing dowel joints must be drilled in advance. The drilled hole should be slightly smaller than the diameter of the nail. Since the wood does not crack so much, the nails can be placed closer to each other in this way. Besides, load bearing capacity the nail joint will increase and the thickness of the wood may be reduced.

Single shear dowel connections used when compressed and stretched rods from boards or beams must be attached to the beams (Fig. 20). In this case, the nails only pass through one connecting seam. They are loaded there perpendicular to the bore shaft and can bend if too much force is applied. Since shear forces also occur in the connecting seam in the body of the nail, this section plane is called the cut plane. In the case of paired connection of plank rods on the planes of the main beam, there are two single-shear dowel joints opposite each other.

Rice. 20. Single shear stud connection

At double shear dowel joints the nails pass through the three pieces of wood to be joined (fig. 21). Nails have two shear planes, since they are loaded in both connecting seams with an equally directed force. Therefore, the bearing capacity of a double-shear-loaded nail is twice that of a single-shear one. In order for the double-shear dowel joints to not disperse, half of the nails are hammered on one side, and the other half on the other. Double-shear dowel joints are mainly used if the free-standing trusses consist entirely or predominantly of planks or beams.

Rice. 21. Double shear stud connection

Minimum thicknesses of timber and minimum nailing depth

Since thin wooden elements are easily split when hammering in nails, the boards for supporting rods, belts and planks must be at least 24 mm thick. When using nails from size 42/110, use even larger minimum thicknessesa(fig. 22). They depend on the diameter of the nail. With pre-drilled dowel connections, the minimum wood thicknesses can be reduced than with simple nailing, as there is less risk of cracking.

Rice. 22. Minimum thickness and driving depth

Removing the tip of the nail from the closest cutting plane is called the driving depth. s(see fig. 22). It depends on the diameter of the nail dn and has a different value for single-cut and double-cut nail connections. Single shear loaded nails must have a driving depth of at least 12d n. However, for certain special nails, a driving depth of 8d n is sufficient due to the higher holding force due to the special profiling. For double-shear connections, a driving depth of 8d n is also sufficient. At a shallower driving depth, the bearing capacity of the nails decreases. If the nails have a driving depth of less than half the required, then they cannot be taken into account for the transfer of forces.

Minimum distance between nails

Fastening of formwork, battens and filly, as well as rafters, battens, etc. acceptable with less than four nails. However, in general, at least four nails are required for each seam or multi-cut nail joint designed to transmit forces.

The uniform arrangement of these nails on the plane of the connection is made using nail marks(fig. 23). So that two nails located one behind the other do not sit on the same fiber, they are shifted relative to the point of intersection of mutually perpendicular nail marks by the thickness of the nail in both directions. In addition, the minimum distances must be observed. They depend on whether the direction of force is parallel or across the fibers. Next, you need to monitor whether the ends of the rods or the edges of the wood will be loaded by the force acting in the joint or not. Since there is a risk of cracking with loaded rod ends or edges, large distances from the edges to the nails must be maintained.

Rice. 23. The minimum distance between nails with a single shear connection

At single shear nail connection vertical or diagonal tensioned bar with nails with a diameter of d n ≤ 4.2 mm, the minimum distances shown in fig. 23. When using nails with a diameter d n> 4.2 mm, these distances should be slightly increased. If the nail holes are pre-drilled, then in most cases smaller distances are required.

At double shear nail connections nails are arranged in ledges. Between the risks of a single-shear nail connection, additional risks are drawn with a minimum distance of 10d n (Fig. 24).

Rice. 24. Minimum distances between nails with a double shear connection

Device of nail connections

When making nail connections, nails must be driven vertically into the wood. In this case, the head of the nail should only be slightly pressed into the wood so that the wood fibers at the junction are not damaged. For the same reason, the protruding ends of the nails can only be bent in a special way. This should only happen perpendicular to the fibers. To apply the location of the nails, as a rule, appropriately drilled templates made of thin plywood or tin are used. In the case of plywood templates, the holes are made of such a diameter that the heads of the nails can pass through them. In the case of templates made of tin, the locations of the nails are marked with a brush and paint.

Nail connections with steel plates

Nail connections with steel strips can be divided into three types, namely, joints with embedded or outside lying plates with a thickness of at least 2 mm and connections with embedded plates less than 2 mm thick.

Outside overlays usually have in advance drilled holes(fig. 25). They are applied over the joint of the beams or boards at the end and nailed with the appropriate number of wire or special nails. At embedded linings with a thickness of at least 2mm nail holes must be drilled simultaneously in the timber and in the lining. In this case, the diameter of the holes must correspond to the diameter of the nail. Embedded linings less than 2 mm, of which there can be several at the joint, can be punched with nails without preliminary drilling (Fig. 26). Such connections can only be made with specially designed spline tools and only with special approval from the authorities.

Rice. 25. Connection by means of a perforated steel plate-lining

Rice. 26. Nail connection with embedded steel linings (Graim)

Connections with nail gussets

Nail gussets are used for the rational manufacture of wooden half-timbered trusses from single-row sections of wood (Fig. 27). For this, wooden rods of the same thickness are cut to length, impregnated and fitted exactly to each other.

Rice. 27. Connection with a nail gusset

In this case, the moisture content of the wood should not exceed 20%, and the difference in thickness should not be more than 1 mm. In addition, the rods should not have any cuts or edges.

The nail gussets must be positioned symmetrically on both sides and, using a suitable press, press into the wood so that the nails sit in the wood for their entire length. Hammering the nail gusset with a hammer or the like is not permitted.

Fastening with nail gussets creates at the nodal points a connection or joints that are strong in compression, tension and shear without weakening the load-bearing section of the wood. For the transfer of forces, the working area of ​​the connection of the nail gusset is of primary importance (Fig. 28). It corresponds to the contact area of ​​the nail gusset with the wood, with the exception of the edge strip with a minimum width of 10 mm.

Rice. 28. Working area of ​​the connection at the nail gusset

Trusses with connecting rods by gussets are industrially manufactured only by licensed enterprises, delivered ready-made to the construction site and installed there.

The need to expand or lengthen a wooden blank is due to the limited cross-sections and lengths of boards and beams available to the joiner due to sawing trees.

There is also a need to connect two or more wood blanks in the transverse or oblique directions when you want to create a frame product using wood and other materials. Joinery connections are made by gluing, using sockets and grooves, which are connected to each other in the parts to be joined.

These connections are called splices. They represent the connection of two or more wooden blanks with their plates or edges, respectively, the result is wood product with dimensions that cannot be obtained from a whole piece of wood.

There are two different groups of docking joints

• joining two simply planed and glued parts with ends or edges;
• the second group of joints presupposes the presence of reinforcing elements such as tenons or a tenon and groove connection.

Plane splice, or butt joint along the length

Plane splice is performed by gluing the straight edges of the boards. It is considered not very durable. The strength of such a joint depends to a large extent on the thickness of the parts to be joined, on the resulting contact between the surfaces of the parts to be joined, as well as on the type of adhesive that can easily change under the influence of atmospheric and thermal conditions.

Half-wood plane splice

When connecting two parts in a half-tree, a groove is made in both parts in half the thickness so that during assembly, the groove of one part is exactly aligned with the groove of the other. This type of connection allows you to obtain a larger area of ​​the joint surface, bonded with glue, than in the previous case, and also allows the possibility of reinforcing the joint using screws or plug-in spikes. It is used in the construction of decks and frame supports.

It is widely used for joining workpieces in the form of boards. Portable milling machines are used to make the holes for the plugs.

Zigzag splicing

The connection is very effective when it is necessary to eliminate the lateral movement of the joint. To obtain such a connection, a molding and planing machine and an appropriately shaped cutter are required. The greater the incline of the cut, the larger the glued surface, the higher the strength of such a connection.

A zinubel plane with fine teeth on the cutting edge creates shallow grooves on the surfaces of the parts to be joined. It is used for gluing large surfaces.

Plane splice or butt joint reinforced with pins

The joint is reinforced with wooden studs inserted up to the middle of the thickness of the wooden parts to be joined. These studs can vary in performance, depending on what degree of connection you want to get.

Figure 1. Alternating groove and tongue connection Figure 2. Groove and tongue connections with shaped tongue-and-groove piles

Splicing with dowels

The assembly of this joint is carried out using a tongue (or pin) and a groove (or groove), therefore it is called a groove and tongue joint.

Wooden parts are used in many products. And their connection is an important process on which the strength of the entire structure depends.

For the manufacture of furniture and other wood products, dozens are used different connections... The choice of the method of joining wood parts depends on what the product should be in the end and what kind of load it should carry.

Connection types

When connecting wooden parts, you need to remember important point- always a thin part is attached to a thick one, but not vice versa.

According to the mutual arrangement of the elements, the following methods of joining wood parts are distinguished:

• building - increasing the height of the part;
• splicing - elongation of the workpiece;
• rallying - increasing the width of the element;
• knitting - connection at an angle.

The methods of joining wooden parts in the manufacture of furniture are most often used as follows:

• gluing;
• "dovetail";
• end-to-end;
• groove;
• overlap;
• deaf on thorns;
• through spike.

Let's consider the technologies of some compounds in more detail.

Splice lengthwise

This kind of wooden parts has some nuances. In essence, this is the elongation of elements in the horizontal direction. Splicing can be:

• End-to-end - the ends are cut at right angles and aligned with each other. A bracket is hammered into both beams (logs).
• Oblique butt - the cuts are made at an angle, and the ends are fastened with a pin or nail.
• End butt with a comb.
• Straight overlay - the cutting length is 1.5-2 times greater than the thickness of the bar (log).
• Oblique pad - the ends are cut at an angle and fixed with bolts.
• A lining with an oblique cut - at the ends of the parts, end ridges are made, having a width and length of one third of the thickness of the bar.

Height extension

From the name it is clear that the essence lies in lengthening the beams or logs in the vertical direction. The axes of the elements are on the same vertical line. The types of building are as follows:

• Build-up end-to-end. A barbed pin is inserted at the sides to absorb accidental loads.
• Extension with one or two thorns. The width and height of one spike must be at least one third of the thickness of the bar. The depth of the nest is slightly more than the height of the thorn.
• Growing in half a tree. The ends of both logs must be cut to half their thickness by 3-3.5 diameters in length.
• Build up the tongue. In one beam, you need to cut a fork into which you need to insert the correspondingly cut end of another workpiece. The connection itself must be wrapped in tin.

Rallying in width

Used to increase the width of the product. When using rallying methods, it is important to pay attention to the location of the tree's annual rings. It is important to alternate the boards depending on their direction. Rallying options are as follows:

• End-to-end - details need to be cut and squared in a square.
• In tongue and groove - the height and width of the ridge is equal to 1/3 of the thickness of the board.
• In a hacksaw - the edges must be cut at an acute angle to the wide plane of the board.
• A comb with a height of 1/3 to half of the board.
• A quarter with a ledge equal to half the thickness of the board.
• In the groove with strips - in each board, select the grooves into which you need to insert a strip that has a width twice the depth of the groove.

Knitting

Knitting is used when it becomes necessary to join parts at an angle. Types of knitting are as follows:

• knitting in half a tree using a secret thorn;
• knitting in a half-paw;
• single and double slotted tenons;
• slotted paw.

to the butt

The easiest way to put two pieces together. Right angle joining of wood pieces is done using this method. The surfaces of the two parts are carefully matched to each other and pressed tightly. Wooden parts are connected with nails or screws. Their length should be such as to pass through the first part and go deep into the second by about 1/3 of the length.

For the fastening to be reliable, it is necessary to drive in at least two nails. They need to be placed on the sides of the center line. The thickness of the nail should not cause the wood to crack. Therefore, it is recommended to pre-make holes with a diameter of 0.7 of the thickness of the nail used.

To enhance fixation, grease the surfaces that are connected with glue. For rooms that will not be exposed to moisture, you can use carpentry, casein or skin glue. If the product is used under conditions high humidity it is better to use a moisture resistant glue, for example, epoxy.

Overlay T-joint

To make such a connection of wooden parts, you need to lay one workpiece on top of another and fasten them to each other using bolts, screws or nails. You can arrange wooden blanks both at a certain angle to each other, and along one line.

To keep the details from changing, use at least 4 nails. If there are only two nails, then they are driven in diagonally. For a stronger hold, the nails must go through both parts, and the protruding ends must be bent and deepened into the wood.

Half-tree connection

To make such a connection of two wooden parts, certain skills and experience are required. It is performed as follows. In both blanks, samples are made with a depth that corresponds to half of their thickness. The sampling width must be equal to the part width.

The method of joining wooden parts in a half-tree can be performed under different angles... In this case, it is important to ensure that the angle is the same on both pieces of wood, and the width matches the width of the part. Due to this, the parts are tightly pressed against one another, and their edges are located in the same plane.

In addition, such a connection can be complete or partial. In the case of a partial connection, the end of one blank is cut at a certain angle, and at the end of the other, a corresponding cut is made. Such compounds include an angular mustache in a half-tree. The bottom line is to trim both studs at an angle of 45 °, as a result of which the seam between them is located diagonally. When using this method, you need to be especially careful, and make the corner cuts with a special tool - a miter box.

Cleat

Such wooden parts are used for fixing planks or for flooring. The edge of one board has a spike, and the edge of the other has a groove. Accordingly, the fastening occurs when the tenon enters the groove. This connection looks very neat, since there are no gaps between the boards.

Making tenons and grooves takes some experience. And besides, a special machine is required for manufacturing. Therefore, it is easier to purchase ready-made parts.

Socket-tenon connection

The most commonly used method of joining wooden parts. This joint is strong, rigid and looks as neat as possible. To make such a connection, you need to have some skills and experience, as well as be attentive. An improperly made socket-tenon connection is fragile and looks ugly.

Its essence is as follows. At the end of one workpiece, a groove is drilled or hollowed out, and a spike at the end of the other. It is better when the elements are of the same width. If the thickness is different, then the spike is made in a thin part, and the groove, respectively, in a thick one.

Spike Sequence:

• Using a thickness gauge, draw two parallel lines on the side of one workpiece. The distance should be the width of the future spike. For its evenness, markings should be made on both sides.
• The most optimal tool for making thorns is a hacksaw with a narrow blade and fine teeth, or a bow saw. During operation, the teeth of the tool must pass along the inner edge of the marking line. For convenience, it is better to clamp the part in a vice. It is best to make the spike slightly larger than the required size. Then, if necessary, you can remove the excess. But if the spike is shorter, then the whole process will need to be repeated again.
• Using a chisel or chisel, a socket (groove) is made in the second part. Naturally, the dimensions of the groove must correspond to the dimensions of the tenon. It is best to drill holes along the entire perimeter of the groove before starting chiselling. The edges are neatly cut with a chisel.

If the connection of the wooden parts is done correctly, then the surfaces of the edges of the thorns adhere tightly to the walls of the nest. This gives good adhesion when gluing. To make the fit of the studs tighter, their dimensions should be 0.2-0.3 mm more sizes nests. If this value is exceeded, the bowstring may split; if the tolerance is less, the mount will lose its strength during operation.

In addition, such a connection also involves gluing and fastening with screws, nails or wooden dowels... To simplify work, holes should be drilled before screwing in the screws. The heads of the screws are hidden in a recessed hole (made with a countersink). The pilot hole should be 2/3 of the screw diameter and less than 6 mm (approximately) of its length.

Gluing

The gluing of wooden parts is carried out as follows:

• The surfaces to be glued are cleaned with a lint-free cloth, and roughness is smoothed with fine emery.
• Using a cardboard stick, apply the joiner's glue in an even thin layer over all necessary surfaces.
• Glue-smeared surfaces should be rubbed against each other. This will provide an even touch and a strong bond.
• The parts must be pulled together so that the retention at the joints is reliable. Measurement of the diagonals will make sure that the corners are straight. They must be equal. If this is not the case, the position of the elements needs to be corrected.
• The connection is strengthened by drilling pilot holes into which finishing nails or screws are driven. The screw heads must be recessed; for this, the holes must be bored. The nails are deepened using a punch.
• Holes with nails are covered with wood putty. The holes bored for the screws are closed with hardwood plugs, greased with glue. When the glue or putty is dry, the surface is smoothed with emery so that it is smooth and then varnished.

Required tools and fixtures

The tools for execution are very diverse. They are chosen depending on the type of work performed. Since in the carpentry the processed elements are larger than in the joinery, accordingly, the tool must be suitable.

To connect wooden parts, use the following:

• axe;
• planer, straight and curved planes, bear, scherhebel - more thorough surface treatment;
• chisel - chiselling holes and sockets;
• chisel - for cleaning cuttings;
• drills with different tips - for through holes;
• various saws - for sawing up and down;
• hammer, hammer, sledgehammer, mallet;
• square, compass, level and other auxiliary tools;
• nails, metal staples, bolts with nuts, screws and other products for fastening.

Conclusion

In fact, there are many more ways to connect wooden pieces of furniture or other structures. The article describes the most popular execution methods and technologies. It is important to remember that the connection of wooden parts for painting or varnishing must be carefully prepared, and all fasteners must be strong and made to last.

In addition to processing solid pieces of wood, it is often necessary to combine wooden parts into knots and structures. Connections of elements of wooden structures are called landings. Joints in timber structures are defined by five types of fits: tight, tight, sliding, loose, and very loose.

Nodes - these are parts of structures at the joints of parts. Connections of wooden structures are divided into types: end, side, corner T-shaped, cruciform, corner L-shaped and box corner joints.

Joinery connections have over 200 options. Here, only the joints that are used in practice by joiners and carpenters are considered.

End connection (extension) - connection of parts along the length, when one element is a continuation of the other. Such connections are smooth, serrated with spikes. Additionally, they are fixed with glue, screws, overlays. Horizontal end connections withstand compressive, tensile, and bending loads (Figure 1-5). Lumber is built up in length, forming at the ends vertical and horizontal toothed joints (wedge lock) (Fig. 6). Such joints do not need to be under pressure during the entire bonding process, as significant frictional forces act here. Milled sawn timber toothed joints meet the first class of accuracy.

The joints of timber structures must be made carefully, in accordance with the three accuracy classes. The first class is for measuring tool high quality, the second class - for furniture products, and the third - for building parts, agricultural tools and packaging. Lateral connection by the edge of several boards or laths is called rallying (Fig. 7). Such connections are used in the construction of floors, gates, carpentry doors, etc. Plank and slatted panels are additionally reinforced with crossbars and tips. When covering ceilings and walls, the upper boards overlap the lower ones by 1/5 - 1/4 of the width. The outer walls are sheathed with horizontally laid overlapping boards (Fig. 7, g). The upper board overlaps the lower one by 1/5 - 1/4 of the width, which ensures the drainage of atmospheric precipitation. The connection of the end of the part with the middle part of the other forms a T-shaped connection of the parts. Such compounds have big number options, two of which are shown in Fig. 8. These connections (knitting) are used when joining the lag of floors and partitions with the harness of the house. The connection of parts at a right or oblique angle is called a cruciform connection. This connection has one or two grooves (Fig. 3.9). Cruciform connections are used in roof and truss structures.

Rice. 1. End connections of beams that resist compression: a - with a straight overlay in a half-tree; b - with an oblique overlay (on the "mustache"); c - with a straight overlay in a half-tree with a joint at an obtuse angle; d - with an oblique lining with a spike joint.

Rice. 2. End connections of beams (build-up) that resist stretching: a - in a straight laid on lock; b - in an oblique patch lock; c - with a straight overlay in a half-tree with a joint in an oblique thorn (in a dovetail).

Rice. 3. The end connections of the bending resisting beams: a - with a straight overlay in a half-wood with an oblique joint; b - with a straight overlay in a half-tree with a stepped joint; c - in an oblique patch lock with wedges and a thorn joint.

Rice. 4. Splice joint with reinforcement wedges and bolts.

Rice. 5. End connections of the bars, working in compression: a - butt-end with a secret hollowed-out spike; b - end-to-end with a hidden plug-in thorn; c - with a straight overlay in a half-tree (the connection can be bolted); r-s straight half-wood overlay with wire fastening; d - with a straight overlay in a half-tree with fastening with metal clips (clamps); e - with an oblique pad (on the "mustache") with fastening with metal clips; g - with an oblique pad and bolted; h - marking of the slanting lining; and - end-to-end with a hidden tetrahedral spike.

Rice. 6. End augmentation of the milling scheme for end gluing of workpieces: a - vertical (along the width of the part), toothed (wedge-shaped) connection; b - horizontal (along the thickness of the part), toothed (wedge-shaped) connection; c - milling a gear connection; d - sawing out the toothed joint; d - milling the gear joint; e - connection to the end and gluing.

Rice. 7. Planks rallying: a - on a smooth joint; b - on a plug-in rail; c - in a quarter; d, e, f - in the groove and ridge (with various shapes of the groove and ridge); w - overlap; h - with a tip in the groove; and - with a quarter tip; k - with overlap.

Rice. 8. T-shaped joints of the bars: a - with a secret oblique thorn (in the paw or in the dovetail); b - with a straight stepped pad.

Rice. 9. Cross connections of bars: a - with a straight overlay in half a tree; b - with a direct overlap of incomplete overlap; c - with landing in one socket

Connections of two parts with ends at right angles are called angular. They have through and non-through thorns, open and laterally, half-way overlapping, half-tree, etc. (Fig. 10). Corner joints (knitting) are used in incorrect window blocks, in the joints of greenhouse frames, etc. A spike connection in the dark has a spike length of at least half the width of the connected part, and the groove depth is 2 - 3 mm longer than the spike length. This is necessary so that the parts to be joined easily mate with each other, and after gluing, there is room for excess glue in the socket of the spike. For door frames, an angular spike connection is used in the dark, and to increase the size of the connected surface, it is in semi-darkness. Double or triple stud increases the strength of the corner joint. However, the strength of the connection is determined by the quality of its implementation. V furniture production a variety of corner box joints are widely used (Fig. 11). Of these, the simplest is an open end-to-end tenon connection. Before making such a connection, spikes are marked on one end of the board with an awl according to the drawing. By marking the lateral parts of the thorn with a file with fine teeth, they make a cut. Every second cut of the thorn is hollowed out with a chisel. For a precise connection, first sawed and hollowed out the stud slots in one piece. It is applied to the end of another part and crushed. Then they saw through, hollow out and connect the parts, cleaning the connection with a plane, as shown in Fig. eleven.

When connecting parts on a "mustache" (at an angle of 45 °), the angular knitting is fixed steel inserts as shown in fig. 12. At the same time, make sure that one half of the insert or fastener goes into one part, and the other half into the other. A wedge-shaped steel plate or ring is placed in the milled grooves of the parts to be joined.

The corners of the frames and boxes are connected with a straight open end-to-end spike connection (Figure 3.13, a, b, c). With increased quality requirements (from the outside, the spikes are not visible), angular knitting is performed by an oblique connection in the direction, a groove and a ridge or an oblique connection on a rail, as shown in Fig. 13, d, e, f, g and in Fig. fourteen.

A box-shaped structure with horizontal or vertical transverse elements (shelves, partitions) is connected using corner T-shaped joints shown in Fig. 15.

In the connection of the elements of the upper belt timber trusses corner cuts are used with the bottom. When the truss elements are mated at an angle of 45 ° or less, one cut is made in the lower element (tightening) (Fig. 16, a), at an angle of more than 45 ° - two cuttings (Fig. 16.6). In both cases, the end cut (cut) is perpendicular to the direction of the acting forces.

Additionally, the nodes are secured with a bolt, washer and nut, less often with brackets. Log walls houses (log cabins) from horizontally laid logs in the corners are connected with a cut "in the paw". It can be simple or with an additional spike (paw with a pit). The marking of the cut is performed as follows: the end of the log is cut into a square, to the length of the side of the square (along the log), so that after processing a cube is obtained. The sides of the cube are divided into 8 equal parts. Then 4/8 part is removed from one side from below and from above, and the remaining sides are performed, as shown in Fig. 17. Templates are used to speed up the marking and the accuracy of making the cuts.

Rice. 10. Corner end joints of blanks at right angles: a - with a single opening through a thorn; b - with a single through secret thorn (in the dark); with single a deaf (blind) thorn in the dark; d - with a single through semi-secret thorn (semi-dark); d - with a single deaf thorn half-dark; e - with a triple open through thorn; g - in a straight overlay in a half-tree; h - through the dovetail; and - in the eyelets with undercut.

Rice. 11. Box corner joints with straight through thorns: a - cutting out the thorn grooves; b - marking the thorns with an awl; в - connection of a spike with a groove; d - processing the corner joint with a plane.

Rice. 12. Corner end connections at right angles, reinforced with metal inserts - buttons: a - 8-shaped insert; b - wedge-shaped plate; in-rings.

Rice. 13. Box corner joints at right angles: a - straight open through thorns; b - oblique open through thorns; c - open through thorns in the dovetail; d - groove for a plug-in rail end-to-end; d - in the groove and comb; e - on plug-in thorns; g - on thorns in a dovetail half-dark.

Rice. 14. Oblique (on "mustache") box connections at right angles: a - oblique thorns in the dark; b - oblique connection on a plug-in rail; in - oblique connection on thorns in the dark; d - oblique connection, reinforced with a triangular strip with glue.

Rice. 15. Straight and oblique connections of workpieces: a - for double connection in oblique groove and ridge; b - on a straight groove and ridge; в - on a triangular groove and a ridge; d - on a straight groove and ridge in the dark; d - on straight through thorns; e - on round plug-in spikes in the dark; g - on a thorn in a dovetail; h - on the groove and ridge, reinforced with nails.

Rice. 16. Nodes in truss elements.

Rice. 17. Conjugation of the logs of the walls of the blockhouse: a - a simple paw; b - a paw with a wind spike; c - paw markings; 1 - wind spike (pit)