When making homemade wooden furniture The master is faced with the need to make high-quality tenon joints. The tenon connection of parts is the highest quality and most reliable. And although in Lately more and more furniture is made and assembled using metal corners, the thorn does not give up its position. Not many people can simply make high-quality spikes. If a person can do them, we can say that he has already established himself as a carpenter.

In industry, studs are said to be “cut” using special precision equipment. At home, it is, of course, not available. Therefore, many craftsmen who make simple garden and country furniture, sacrifice quality for simplicity. Let me also remind you that tenons are cut in the vast majority of cases only along the wood fibers. If the tenon is made narrow and across the fibers, it will definitely chip. To prevent it from chipping, the width of the tenon should be at least 15-20 times the thickness of the part. This requirement does not apply to plywood. You can cut tenons of any width into plywood, but it is desirable that the outer layers are also oriented along the tenon.

Meanwhile, for a long time there has been a fairly simple method that allows you to quickly and efficiently make tenon joints wooden parts even a novice carpenter. This method was proposed by Yu.A. Egorov. The essence of the method is quite simple and understandable.

Let's say we need to make a finger joint between two parts. For convenience, in the drawings I colored them in different colors.

Prerequisite for high quality workmanship tenon joint is the fact that each saw has a specific cutting width. It is determined by the size of the tooth set. It can be measured by making several cuts in some piece of wood. Or you can directly use the saw to take measurements when making tenons.

On each part we apply a mark to the depth of the cut; it is equal to the thickness of the parts. If the parts are the same in thickness, then the depth of cut in each part will be the same. If the items have different thickness, then the depths of the cuts will be different. In a thin part the cuts are deeper (equal to the thickness of the thick part), in a thick part they are shallower.

The parts are folded face to face so that the ends coincide, and relative to each other along the side edges they are shifted to the width of the cut of the saw that we will use to make tenons. (Not the thickness of the saw blade, but the width of the cut!). We secure the parts in a vice or workbench and make random cuts evenly across the entire width of the parts. If the parts are of different thicknesses, we make cuts to a depth equal to the thickness of the thin part. (We will finish the thin part separately later). We try to make the cuts as much as possible along the axis of the part, avoiding the taper of the tenons.

After this, we release the parts and again shift them relative to each other by the width of the cut, but only in the other direction. By the way, if we now make a shift by an amount slightly less than the width of the cut, then we will subsequently obtain a tight tenon joint, which is important for furniture. And if we move the parts a little more than the width of the cut, we will get a free tenon joint. The tenons of the parts will fit freely into the grooves of the other part. This circumstance is important in the manufacture of detachable connections (on a stud) or rotary connections.

Ignoring the old cuts, we make new ones, approximately in the middle of the existing tenons. We also observe the depth of the cuts and especially carefully their length.

After this, we release the parts and adjust the depth of the cuts to the required value (for a thin part, if the parts are of different thicknesses). Using a chisel, we carefully remove excess tenons (look carefully and do not remove the ones you need!), and clean the ends in the grooves.

After this, the parts can be joined.

Permanent connections are usually made with glue. For wooden parts, wood glue or PVA glue are perfect. They will maintain a reliable connection even if the parts get wet or the moisture content of the wood increases. If the parts will be used in a dry room, you can also use epoxy resins(adhesives).

After the glue has hardened, the joint is cleaned, sanded and processed in the same way as the entire product.

If the connection is planned to be detachable or rotating (for example, you are making blinds or an accordion door from boards or panels), then before starting assembly, you need to round the ends of the tenons so that their corners do not rest against the grooves when turning. In non-rotating but detachable connections, this is, of course, not necessary.

Having connected the parts, all the tenons are simultaneously drilled with a long thin drill. Its diameter should be equal to the diameter of the pin (nail) that you will use as an axis or fastening.

Using this method of making tenon joints, you can quickly, easily and most importantly, make very high quality tenons on the parts of your garden furniture.

Short path http://bibt.ru

Chapter III BASIC TYPES OF JOINERY CONNECTIONS

§ 11. Types of tenons for joining joinery. Tenon joints wood

The pieces of joinery are connected to each other by means of a tenon joint, consisting of two elements - a tenon and a socket or eye. A tenon is a protrusion at the end of a bar that fits into the corresponding socket or eye of another bar.

Spikes are single(Fig. 44, a), double(Fig. 44, b), multiple(Fig. 44, c), i.e. more than two.

Rice. 44. Types of thorns:

a - single, b - double, c - multiple, d - round, d - « dovetail", e - one-sided dovetail, g, z - jagged, i - socket, k, l - eyes, m - blind thorn, n - thorn in the dark, o - thorn in the semi-dark

Solid spike- this is a spike that is integral with the bar. An insert tenon is a tenon made separately from the bar. A tenon with a cross-section in the form of a circle is called round (Fig. 44, d).

Dovetail spike(Fig. 44, e) has a profile in the form of an equilateral trapezoid with a large base on the end face of the tenon, a one-sided dovetail tenon is in the form of a rectangular trapezoid with a large base on the end face of the tenon.

Jagged Spike has a profile in the form of a triangle or trapezoid, the smaller base of which is the end face of the tenon (Fig. 44, h), double-edged serrated tenon(Fig. 44, g) - an isosceles triangle.

Single and double spikes used in the manufacture of windows, frame doors, furniture; dovetail spike - with making boxes, boxes; serrated tenons - for adhesive joining of parts (splicing) along the length.

In addition, round insert tenons are used when connecting plots (blanks) across the width. Spikes in darkness and semi-darkness (Fig. 44, n, o) are used in the manufacture of frames, furniture, etc.

A tenon in the dark is made not only at the end connection, but also in cases where it is required that the edges of the nest are invisible, since it is not always possible to obtain smooth edges of the nest. To hide this defect, the darkness is cut out from the tenon, that is, part of the tenon width is removed from one or both sides.

In order to form a tenon or an eye, it is necessary to pre-mark the processed bars, that is, planed on four sides to the required size.

" onclick="window.open(this.href," win2 return false >Print
Email

Details Category: Wood and Timber

Tenon joints of bars

General information. The main compound in woodworking is thorny. It consists of two elements: spikes and sockets (eyes). Spikes there are whole And plug-in. Solid spikes made at the ends of parts to be connected. Solid spikes are usually flat. Insert tenons can be flat or round. In terms of the strength of connections, solid and inserted tenons are the same. Spikes may be through and blind. Through tenon when connected to an eyelet or through-hole socket, it passes through the mating part. Blind thorns mated with non-through sockets, the depth of which is at least 2 mm greater than the length of the tenon.
The number, shape and size of the tenons significantly affect the strength of the connection. With an increase in the number of spikes, the gluing area and the strength of the connection increase, but the time for its production increases.
The strength of carpentry joints also depends on the quality of the wood, the accuracy of manufacturing of the joint elements, the quality of the glue and gluing conditions. There should be no wood defects on the connection elements, and the connection itself should not have gaps or cracks.

Connecting the ends of parts in half a tree. Such connections can be along the length, end and middle(Figure below). They are quite simple to manufacture, but have low strength during operation.

Joining wood into half a tree:
A - by lenght;b - corner; V - middle.

Corner end connections (UK). The greatest simplicity and high strength are characterized by connections using open straight through tenons. A significant disadvantage of these connections is that the ends of their elements are visible on both sides of the part, which worsens the appearance. Therefore, such connections are used in those structures where it is possible to cover the tenons with overhead parts or parts in contact with them.
Open through single tenon connection (UK-1); spike thickness ( S 1) and shoulder ( S 2) in this compound is calculated using the following formulas (Fig. below, A ):

S 1 = 0.4S 0 ; S 2 = 0.5(S 0 – S 1),
Where S 0- thickness of the part.

More durable compounds of this group are compounds on open through double UK-2(rice. b ) And triple UK-3 thorns(rice. V ). To make such connections you need exact dimensions and sawing out connection elements.
Tenon connections with semi-darkness, (rice. g, d ) have more complex shape, and therefore more difficult to manufacture. The thickness of the tenons of these connections is calculated similarly to the thickness of the connection UK-1.
These connections can be manufactured with non-through tenon UK-4(rice. G ) And through tenon UK-5(rice. d ). By connection strength UK-4 And UK-5 inferior to the compounds discussed above. They are used in cases where high joint strength is not required and it is necessary to avoid damage to the appearance of a part mated to the end of another part.

Tenon connections with darkness(rice. g, f ) can be with end-to-end UK-7 And non-through UK-6 thorn. The thickness of the tenon and shoulders is determined in the same way as in connections with a semi-darkness with an open end-to-end single tenon.

Connections for round plug-in tenons (dowels) somewhat inferior in strength to connections made with straight open tenons. However, they save some wood. Previously, dowels were made mainly from hard hardwood wood, but now dowels made of plastic are also widely used. These connections are also characterized by ease of manufacture. To do this, it is necessary to drill holes of the required diameter, install spikes on the glue and hold the mating parts under pressure. The diameter of the dowel in a connection with round dowels is calculated using the following formula: d = 0.4S 0.
In connection UK-9 The use of through spikes is allowed (Fig. And ).

Miter connections with insertable flat tenon can have through (UK-11) And non-through (UK-10) thorns(rice. k, l ). These compounds are characterized by low strength and more complex manufacturing compared to connections with round dowels. They have beautiful appearance and provide uniformity in finishing (especially non-through ones). Thickness of tenon joints UK-10 And UK-11 determined by the formula S 1 = 0.4S 0 . A miter connection with a double plug-in tenon is allowed, while S 1 = 0.2S 0 .
Gear connection UK-12- This the new kind connections, the elements of which are made on machines.

You can successfully make and fit this time-tested connection, no matter what tools you have at your disposal. Simply choose one of these proven methods, using a variety of tools, from inexpensive tools you probably have on hand to specialized machines.

Start with the Basics: Basic Rules for Male-Socket Joints

Regardless of how you form your tenons and sockets, these tips will help you achieve perfectly-fitting, strong joints for any project.

Correct connections always start with careful markings. Use a proven steel ruler and square, and mark the marking lines with a sharp pencil, surface planer or marking knife.
A simple rule that is easy to remember: when marking a socket on the end or edge, the thickness of the workpiece must be divided into three equal parts. The outer two thirds will become the walls of the nest, and the middle third must be removed. So, in a board 18 mm thick (picture below) A 6 mm wide nest is made in the center of the edge of the workpiece. When using material with a thickness of more than 18 mm, the width of the socket can be more than one third of the thickness of the workpiece, provided that the thickness of the walls of the socket is at least 6 mm - this is due to strength considerations.

Make the nests first

Method No. 1. Simple drilling jig for dowel connections

The first two methods of removing nests involve drilling a series of overlapping holes and removing excess material between them. The holes should be perpendicular to the edge of the board, and jigs for drilling holes for dowels do an excellent job of this task. They are especially convenient when working with material with a thickness of about 18 mm, for which bushings with a common diameter of 6 mm are suitable, just corresponding to the width of the socket. (Most of these tools have bushings for drilling 6, 8, and 10 mm diameter holes, and some have a bushing for 12 mm diameter holes.) If the drill jig did not come with a drill bit, purchase a twist wood drill bit with a center point - this will cut cleaner and not gives chips on the surface.

To limit the depth of the hole, attach a locking ring to the drill or make a “flag” out of masking tape.

Holding the chisel perpendicular to the edge of the board, carefully cut away any rough edges on the sides of the nest. If the chisel is sharp, you won't need a mallet.

To make a nest, attach the jig to the workpiece, positioning it at the edge of the marked nest so that the edge of the hole just touches the marking lines marking the edge and walls of the nest. Drill a hole, having previously set the required drilling depth. Do the same at the other edge of the socket as shown top left. Now rearrange the jig and drill a few more holes between the two outer holes. After this, drill out the material between them, centering the drill on the bridges between them.

After removing most of the excess material, clean and level the sides of the socket with a chisel. Use the widest chisel that the size of the socket will allow. If you prefer rectangular sockets, trim the corners with a chisel that is the same width as the socket.

Method number 2. The same principle, but using a drilling machine

if you have drilling machine, then for greater productivity and accuracy, use it instead of an electric drill and drilling jig. You will need a stop (at least in the form of a flat board attached with clamps to the machine table) to position the socket and ensure that it is parallel to the edges of the workpiece. Using a square, check that the table is perpendicular to the drill. Install a pointed twist drill or Forster drill into the machine chuck; the central point of such drills prevents the drill from leaving the intended point. Adjust the drill depth stop to match the depth of the socket.

Just as when using a jig, first drill holes at the ends of the future nest. Then drill a series of holes between them, leaving bridges about 3mm wide. After finishing drilling, trim the walls and corners of the socket with a chisel.

Method number 3. Using a plunge router

This technique involves milling the socket with an increase in depth of 6 mm for each pass. In addition to the plunge router, you will need a sharp cutter (we recommend a helix cutter with an upward spiral), as well as a side stop or special device, holding the cutter within the marking lines. You can control the starting and ending points of the milled nest by eye or attach stop bars to the workpiece that limit the longitudinal stroke of the router.

A homemade or factory-made socket milling jig like the one shown in picture above, will be a versatile addition to any workshop. The top plate made of transparent plexiglass allows you to easily align the centering lines of the fixture with the markings on the workpiece. The length and width of the slot hole of the device should be several more sizes sockets taking into account the difference in diameters of the cutter and the copy sleeve moving in the slot hole. Additional expenses for the purchase of a ready-made device, it is compensated quick installation and flexible to customize the size of the nest. Examples of such devices are the Mortise Pal and Leigh Super FMT. The Mortise Pal has a built-in clamp and comes with six socket routing templates different widths and length (additional templates can be purchased separately). The Leigh Super FMT bench jig (www.leighjigs.com) allows you to rout both socket and tenon in one setup. The kit includes guides and cutters for tenons and sockets of five various sizes. Additional guides are purchased separately.

EDGE OF THE BLANKET. When machining narrow workpieces, such as this stand, use a clamp to hold down an auxiliary piece of wood to stabilize the router. END OF THE BLANKET. A simple device creates a wide and stable support surface for the router when making holes in the ends of workpieces.

Method number 4. Drilling square holes is easy

Of course, from a technical point of view, a slotting machine performs not drilling, but chiselling square holes. A rectangular nest is hollowed out around round hole simultaneously with drilling the latter, for which a special auger drill is used, located inside a hollow cutter-chisel (more gentle photo on the left). This method of sampling nests is the fastest, but also the most expensive. Tabletop slotting machines cover almost all of your nesting needs and cost around S225-500, cost floor models starts from $900. (Keep in mind that some specialty machines do not come with cutters and drills, which cost $10-$30 each, with a set of four starting at $40.)

The drill has deep grooves that quickly remove chips, and the external square cutter-chisel forms clean walls of the socket.

The long arm of a slotting machine creates the force necessary to drive the cutter into the workpiece.

Once you set up your slotting machine, you can select such a socket in less than a minute.

This is how a slotting machine works. First, install a chisel with a drill into the machine. Adjust the depth stop to match the depth of the socket. Align the fence parallel to the cutter so that the latter is exactly between the marking lines. Form the ends of the nest first and then remove the material between them by making overlapping holes. If you like this method, but are not ready to buy specialized machine, consider purchasing a slotting attachment for your drill press. Such devices are relatively inexpensive ($65-125). The attachment is installed on the machine quill (photo below) and works exactly the same as a slotting machine. The disadvantage is that you will not be able to use the machine for normal drilling until you remove the attachment.

In just 20 minutes, you can turn a drilling machine into a slotting machine by installing an attachment on the quill.

Now make the spikes and fit them to the sockets

Plug-in tenons are convenient to use with milled sockets. Saw off the tenons from a long piece that has been machined to the required section.

Depending on the chosen method of selecting sockets and the tools available, you can make spikes at the ends of the parts, or insert (separate) spikes that connect two parts to the sockets.

The use of insert tenons involves selecting sockets in both parts to be joined, into which a sawn tenon suitable for both sockets is inserted (photo on the right). Instead of buying blanks for inset tenons, you can make them yourself from scraps of hardwood (to be safe, process scraps that are at least 305 mm long). Just sharpen the workpiece to a thickness that ensures a tight fit of the tenon in the socket. If the ends of the socket are semicircular, mill the corresponding roundings on the blanks for the tenons. After this, saw off the tenons of the required length from the workpiece.

Method No. 1. A groove disk will help you quickly deal with spikes

The stackable groove disc allows you to cut tenons from high accuracy And minimal costs time. Fine adjustment of the disc thickness is not required as excess material is removed in a few passes. To cut tenons using this method, use two outer discs, between which install three intermediate chipper discs with a thickness of 3.2 mm. To prevent chipping at the exit of the disc from the workpiece, attach a plywood or MDF pad to the transverse (angular) stop of the sawing machine.

After installing the mortise disk in the machine, adjust its extension so that it just touches the tenon marking line on the workpiece. Using a piece of material the same thickness as the workpiece, make one pass on both sides and check the fit of the resulting tenon. Adjust the blade offset and make test passes again. The result should be a tight fit of the spike in the socket.

THE GROOVE DISC SIMULTANEOUSLY FORMS THE SHOULDERS AND CHEEKS OF THE TENON

The grooving disc works quickly and is easy to use, but often leaves characteristic marks in the form of scratches that require additional cleaning.

First, use a groove disc to cut out the front cheeks of the tenon, and then the side ones. The high overlay of the cross stop will provide support for the workpiece when cutting out the side cheeks.

Now install the longitudinal (parallel) stop of the machine so that it limits the length of the tenon. Measure the distance between the stop and the teeth of the outer disk farthest from the stop - this distance determines the line of the shoulders of the tenon. Provided that the rip fence is parallel to the saw blade and the grooves for the cross fence, making a pass will not lead to the blade pinching or the workpiece being thrown back. With these machine settings, cut out both face cheeks of the tenon on all workpieces. After this, without changing the position of the longitudinal stop, form the side cheeks of the tenons, adjusting the disc overhang accordingly to obtain the required width thorn. Having finished cutting out the tenons, remove roughness from their cheeks using a zenzubel or a sanding block.

Method No. 2. With a tenoning carriage, the tenons will be smoother

A tenon carriage like the one shown in right photo below, costs about the same as a good mortise disc ($100-150), but it provides a cleaner surface on the tenon cheeks. Set offset saw blade in accordance with the width of the hangers. Then, while pushing the workpiece along with the cross fence, form all four shoulders of the tenon as shown in left photo below. If necessary, when cutting out edge (side) shoulders, adjust the offset of the disc. Pre-forming the hangers ensures they are clean and crisp.

First make the cuts that form the shoulders of the tenon. Feed the workpiece using an angular (cross) fence, using the longitudinal fence as a tenon length limiter.

Adjust the tenon carriage so that after sawing out the tenon cheek, the trim falls freely to the side and is not pinched between the disk and the carriage.

To cut cheeks, simply secure the workpiece standing at the end in the carriage, adjust the carriage by aligning the marking line with the edge of the saw blade, adjust the blade overhang and make the cut. Turn the workpiece over and file the opposite cheek of the tenon. A tenon cut in this way will be located exactly in the center (if the tenon must be shifted to one side of the workpiece, it should be cut at two different installations). Tenoning carriages allow you to form tenons not only at right angles, but their back stop can be tilted. If you want to save money, make a tenoning carriage yourself.

Method number 3. Tenons on a band saw - rough and fast

Setting up a bandsaw for cutting tenons is as easy as setting up a regular saw. rip sawing. Pre-form the shoulders of the tenon on circular saw, as described in “Method No. 2”. After this, set the rip fence of the band saw so that the thickness of the tenon being cut is approximately 0.8 mm greater than required, and make the cut (photo below).

While forming the tenon cheeks, feed the board slowly so that saw blade did not bend and did not result in curved spikes. Be careful to stop feeding the workpiece after the cut falls away to avoid accidentally sawing through the tenon shoulders. Sawn on band saw the cheeks will be slightly rough. For better glue adhesion, make them smooth using a sanding block or a sander.

Method number 4. Why saw if you have a milling table?

You can rout smooth, neat tenons on your router table with just one bit and a crosscut and rip fence. First, insert a straight bit of the largest available diameter into the router collet and adjust its offset along the tenon marking lines. Install the longitudinal stop milling table so that it limits the length of the tenon. In this case, it must be installed parallel to the groove for the transverse (angular) stop - this ensures that the shoulders of the tenon will be perpendicular to the edges of the workpiece.

The gap between the longitudinal stop pads allows you to remove chips with a vacuum cleaner.

Once you've finished setting up, start routing by first making a pass along the end. Consistently perform one pass after another until the end of the workpiece slides along the longitudinal stop. (If you first form the shoulder of the tenon, there is a risk that during subsequent passes the workpiece may be torn out of your hands.)

Using tenons, parts are connected in length, width and at an angle.

Connecting the ends of parts in half a tree. Such connections can be length, end and middle.

For manufacturing, wood is cut down at the mating points to the thickness of the mating part. The length of the connection elements is equal to 2-2.5 times the thickness of the parts being connected. The connection elements are secured together by gluing. Corner End Connections (UK). The greatest simplicity and high strength are characterized by connections using open straight through tenons. A significant disadvantage of these connections is that the ends of their elements are visible on both sides of the part, which worsens the appearance. Therefore, such connections are used in those structures where it is possible to cover the tenons with overhead parts or parts in contact with them. Connection to an open end-to-end single tenon (UK-1); the thickness of the tenon (S1) and shoulder (S2) in this connection is calculated using the following formulas (a): S1 = 0.4S0; S2 = 0.5(S0 – S1), where S0 is the thickness of the part. More durable connections of this group are connections to open end-to-end double UK-2 (Fig. b) and triple UK-3 spikes (Fig. c). To make such connections, precise dimensions and cutting of the connection elements are necessary. Tenon connections with semi-darkness , (Fig. d, e) have a more complex shape, and therefore are more difficult to manufacture. The thickness of the tenons of these connections is calculated similarly to the thickness of the UK-1 connection. These connections can be made with a non-through tenon UK-4 (Fig. d) and a through tenon UK-5 (Fig. e). In terms of strength, the connections UK-4 and UK-5 are inferior to the connections discussed above. They are used in cases where high joint strength is not required and it is necessary to avoid damage to the appearance of a part mated to the end of another part. Tenon connections with darkness (Fig. g, f) can be with a through UK-7 and a non-through UK-6 spike. The thickness of the tenon and shoulders is determined in the same way as in connections with a semi-darkness with an open end-to-end single tenon. Connections for round plug-in tenons (dowels) somewhat inferior in strength to connections made with straight open tenons. However, they save some wood. Previously, dowels were made primarily from hard hardwood, but now dowels made of plastic are also widely used. These connections are also characterized by ease of manufacture. To do this, it is necessary to drill holes of the required diameter, install spikes on the glue and hold the mating parts under pressure. The diameter of the dowel in a connection with round dowels is calculated using the following formula: d = 0.4S0. In the UK-9 connection, the use of through spikes is allowed (Fig. i). Miter connections with insertable flat tenon can have through (UK-11) and non-through (UK-10) spikes (Fig. j, l). These connections are characterized by low strength and more complex manufacturing compared to connections with round plug-in tenons. They have a beautiful appearance and provide uniform finishing (especially non-through ones). The thickness of the tenon of joints UK-10 and UK-11 is determined by the formula S1 = 0.4S0. A miter connection with a double plug-in tenon is allowed, with S1 = 0.2S0. Gear connection UK-12 - this is a new type of connection, the elements of which are performed on machines.

Thorns and their types.

Thorn is a protrusion on a part whose width is less than the width of the part itself. The spikes are inserted into the sockets. The nest must be of such a size that the spike fits tightly into it. At the same time, the tenon cannot be too thick, since when it is driven into the socket, the part may crack. The spike has length, thickness and width. Tire length - this is the distance from the end to the shoulders, thickness - the distance between the shoulders or cheeks, and width - transverse size of the cheek. There are thorns solid and plug-in. Solid spikes are made at the ends of the parts to be connected. Solid spikes are usually flat . Plug-in spines can be flat or round. In terms of the strength of connections, solid and inserted tenons are the same. Spikes may be through and blind . Through the tenon, when connected to an eye or through socket, passes through the mating part. Deaf the spikes are mated with non-through sockets, the depth of which is at least 2 mm greater than the length of the spike. The number, shape and size of the tenons significantly affect the strength of the connection. The shape of the spikes can be round, flat and trapezoidal. The edges of trapezoidal and flat tenons are called cheeks. Shoulders - these are the cut parts of the bar, that is, the surface above which the tenon rises. The end part of the tenon is called butt .

Screws and their types.

Screw(screw from the German schraube) is actually an improved screw that is screwed into soft material(wood) and by deforming the material it forms a thread, that is, it is one of the 6 simplest mechanisms and, depending on the applied force, changes direction or magnitude. Kinds: universal screws - this type is successfully used for the most different surfaces. The station wagon is mainly used in household work– construction and repair. Frequent thread with a countersunk head, which has a slot for a cross thread - distinctive features such screws. Universal screws are made with various types heads: countersunk, semicircular, cylindrical, hexagonal, cross-head. Further - hex screws . They are made of cold-rolled steel and come with dowels. Very durable, used in plumbing and woodworking. Frame screws are threaded throughout the entire shaft; used in the manufacture of various window frames And doorways. There is no need to use a dowel here. Screw ring welded equipped with a steel ring instead of a head. It is used not only in working with wood, but also with concrete and brick. Highlight round screw heads, oval screw heads and flat screw heads. Round heads screws are visible on the surface of the material in the screwed-in state and they are most amenable to unscrewing. Oval heads The screws are screwed in flush, but the head still sticks out a little. Flat heads The screws are mostly invisible and are called countersunk, because when they are screwed in, they become flush with the surface.