From time immemorial, we have built houses from wood. Sometimes completely without the use of other building materials, with the help of only an ax, without a single nail ... Well, you know, right?
Originally Russian technologies are not forgotten. There are still hereditary specialists who will slowly but surely assemble you an authentic hut, as in the good old days. But basically, the methods and approaches have changed significantly - to the topic of the day and in accordance with modern requirements for comfort, energy efficiency, and safety. They have evolved and taken it to the next level. Now we are successfully applying, so to speak, world experience - the developments of builders from other countries, which have long proved their worth.
One of these well-established borrowings is the system of perforated fasteners (which we still rank as innovative), which is designed for quick and reliable assembly of all kinds of frame structures from cut lumber. The elements of this complex system are various angles and brackets, tapes and plates, which are equipped with large quantity pre-prepared holes. A nail plate stands somewhat apart in a large list of fixing devices, we will talk about it later.
What is MZP?
A metal-toothed plate (MZP), or as this fastener is also called a “nail plate”, is a flat rectangular (sometimes square) part made of cold-rolled steel. One of the MZP options is a "studded disc" or "studded strut".
The thickness of the plate can vary from 1 to 2.5 mm, which allows solving a variety of tasks in terms of loads. The thicker the metal, the larger the section of the structural elements the plate can connect. In any case, the steel grade is used so that the product has a balanced combination of ductility and strength.
The general dimensions of the samples sold are usually in the range of 2.5-18 cm in width and up to 30 cm in length. However, of course, the available nomenclature is much wider, many domestic producers offer fast production MZP according to individual, practically unlimited sizes. Terms of cutting the required size of non-standard minimum wages is about 7-14 days.
Like any other version of perforated fasteners, the steel toothed plate is necessarily endowed with a layer of zinc, which protects the fastener from corrosion. For use in open visible structures, the product can be coated with a colored powder coating.
Compared to conventional perforated products with round holes for nails, screws, bolts or anchors - here we have on the surface of the product a large number of spikes extruded from metal using a punching press.
The number of cloves can reach up to 80 pieces per decimeter of the product. Each of them, during installation, enters the tree, where it clings to the fibers, and the fasteners begin to work as a whole. After pressing the MZP, the board or beam no longer chipped in the attachment zone, the forces acting on the assembly can only act on crushing, and load bearing capacity the finished structure because of this only increases significantly. Under extreme loads, the spliced lumber breaks on the array, but does not separate under the nail plate. That is, to compare this hardware with a hundred scattered carnations is at least incorrect.
It should be noted that the height of the spikes in different nail plates may be different. The traditional option teeth can be considered 8-10 mm long, but there are also products with a brushing of 14-15 mm or 25-26 mm. As a rule, there is a dependence and relationship between the thickness of the plate and the height of the tooth (the thicker the MZP - the longer the tooth - the larger lumber can be collected).
It is customary to distinguish between two fundamental options for nail plates, depending on the shape of the spikes:
- With multidirectional notch,
- With unidirectional notch.
Teeth with one direction and angle work fine, but with multi-vector loads, fixation in some directions is considered less effective. In addition, during installation, it is necessary to take a more serious approach to the orientation of the plate relative to the direction of the fibers of the board or beam, which are loaded more in the assembly. The upgraded MZPs with one direction of perforation are endowed with a displacement of studs (staggered type) in each adjacent row, which improves the engagement effect.
Experts are convinced that good performance plates are issued in which the teeth are inclined in different directions (usually two mutually perpendicular), for example, along the diagonals of a rectangular plate or along its length and width. So, in theory, fasteners work equally well with lumber, which has any orientation of the fibers in the array, and also holds loads no matter where they are directed during the operation of the truss. There are also models in which the studding is performed not only in different directions, but also the rows of teeth are tilted at different angles.
Important! The choice of a specific plate model is based on the thickness of the fastener, overall dimensions, number of teeth, their inclination, length, section shape ... There are computer programs that allow you to calculate the appropriate MZP as accurately as possible for any type of structure.
Where is the MSP applied?
The main function of a metal toothed plate is to connect two or more edged boards or bars in the same plane. And best performance reliability will be achieved if the sawn timber is not used wet, which is not prone to drying out and cracking.
The first samples of the MZP began to be used on the patrimony frame housing construction(in North America) at the beginning of the last century. The experience turned out to be successful. In complex spatial structures, toothed plates create a strong fixed connection, acting simultaneously as a reference base plane for frame elements.
Based on them, they collect:
- wall load-bearing frames and panels
- various three-dimensional structures made of wood (for example, stairs),
- powerful formwork,
- longer beams by splicing lumber end-to-end,
- thicker or higher beams by splicing lumber overlay (layers or edges, respectively),
- arched structures made of piece elements (without the use of wood bending).
- complex elements of a wooden roof.
On the this moment in our country, they prefer to buy metal toothed plates mainly for creating roof trusses, which can cover very large spans- up to several tens of meters, with a variety of docking angles. Fasteners are actively used both in industrial and private construction.
Among the benefits we receive are the following:
- There are no restrictions on the maximum length of lumber available for sale,
- The terms for assembling structures are reduced, the laboriousness of operations for connecting elements is reduced (since there is no need to perform cuts or tie-ins, no need to massively turn screws, hammer nails).
- There is no need to purchase ruffed nails or corrosion-resistant self-tapping screws in large volumes, which are very expensive.
- The reliability of the assembled units increases with a decrease in cross sections and mass.
- The amount of wood that goes to waste is reduced.
- Increasing the number of available constructive solutions, especially if you use a specialized software.
There are also some restrictions:
- It will not work to assemble directly on the spot.
- It is necessary to prepare a flat area on the ground or work in the workshop.
- You need to have some of the equipment for secure installation MZP.
What are the nuances of installing nail plates?
- The most important point is that each connection node is fixed with a plate on both sides.
- The platinum with unidirectional teeth should be oriented so that the rows of spikes are parallel to the fibers of the beam or board, which should perform a larger load-bearing function.
- For installation of the MZP, options with a hammer or sledgehammer are not suitable. The pressure is too weak and uneven. Vibration is very harmful, even when struck through spacers, the plate and its spikes can be deformed.
In order for, for example, rafter boards to evenly accept fasteners over its entire area, you need to use a rolling press. Accordingly, the assembly of roof trusses and wall frame sections is mainly carried out in workshops. And only then the frame is transported to the construction site, where it is lifted and secured in place with the help of a crane. - It is still possible to mount the MZP at the facility. To do this, they create a flat, clean working platform on the ground, and use a metal frame (shaped like a clamp) as a pressing device, as well as car jack bottle type, working force which is from 30 tons.
- From lumber prepared in size, the truss is set up on stands, and through the toothed plates with single self-tapping screws, all elements are temporarily fixed in the design position.
- All plates are laid out in the right places.
- An impromptu press is brought under the connection zone with the plate. First, the outer corners of the structure are crimped, and then other joints.
- The MZP is pressed into the wood smoothly until the entire plane of the plate is pressed against the truss array (squeezing, of course, is not welcome). Normally sliced lumber is assembled tightly, although the technology allows gaps between the ends of boards / beams up to 5 mm.
In conclusion, I would like to note that the assembly of complex frame structures from edged lumber with the help of gear plates - slowly, but gaining popularity. Accordingly, the offer for the sale of this interesting fastener is growing very quickly. As practice shows, samples of the minimum wage of very low quality appeared on the market. Not only that, one-day firms that press gear perforated fasteners do not comply with the basic requirements for design spikes, so they can still use low-grade steel with low strength, or a very thin zinc coating that does not last more than a couple of seasons. Therefore, the acquisition of minimum wages must be taken extremely responsibly, giving preference to trusted suppliers. In order for trusses and frames to work as expected, it is also equally important to buy a board or timber of normal quality.
It is a metal plate, on the surface of which there are several rows of spikes made by stamping.
It is they who, during the installation of this fastener, “dig into” the wood and are firmly fixed in it.
Depending on the variety and size, nail plates can have from 2 to 16 rows of spikes, the height of which is usually about 8-14 millimeters.
The fastening element is made of galvanized steel with a thickness of 1 to 1.5 mm by cold stamping, the teeth have a height of up to 14 mm.
What are toothed blades made of?
Serial production of nail (toothed) plates is carried out on a specialized industrial equipment. They are made from galvanized sheet steel.
In the production of this type of fastener, powerful hydraulic presses are actively used, which are characterized by high productivity.
This equipment makes it possible to obtain high-quality and, importantly, relatively inexpensive nail plates in large quantities.
Scope of application of nail plates with GP marking
Metal serrated nail plates are also used as connectors for construction.
They are great for firmly connecting elements together. wooden rafters used in the construction of buildings with large spans.
Mounting plates (toothed) are also used to connect the timber, and it turns out to be very strong and durable. This fastener significantly simplifies and speeds up the assembly of lattice frames.
Benefits of studded mounting plates
Studded fastener connectors have gained wide popularity due to the many advantages and benefits they offer.
The main one is, perhaps, that this fastener guarantees a strong and durable connection. wooden parts. At the same time, the wood does not split, its integrity is preserved.
Due to the presence of a high-quality anti-corrosion coating, the nail plates practically do not rust, which is especially important for such a hygroscopic material as wood.
For the most durable butt joint wooden elements located in the same plane (boards, beams, poles, beams, truss and other structures), high-strength and reliable fasteners are used - (toothed). Them characteristic feature is stamping with teeth 8 or 14 mm high and 1 mm thick, which are arranged in rows on a monolithic metal platform. The bonding strength of the plate depends on the shape of the teeth and their angle of inclination.
Manufactured from high quality 1.2mm thick carbon steel sheet with forged teeth on hydraulic press and subsequent galvanizing. The product is not subject to corrosion, has a long service life and the following benefits:
- provides high strength and durability of connections;
- easily withstands dynamic loads;
- allows you to do without the use of nails and other fasteners;
- significantly increases the speed of work.
Nail plates wholesale
The company "StalKrepezh" manufactures own production nail plates various forms and sizes for use in wooden housing construction, roof construction, formwork construction and other repair and finishing works. At us it is possible at the prices of the producer in any quantity and assortment row. Our consultants will help you make the right choice and place an order.In we wrote that the Kirov enterprise "Steelcap" launched its analogue of the European nail plate GNA20 (our name is GP). This plate is distinguished by a low tooth (8.5 mm) of a specific shape. It was not easy to repeat such a product, but the Kirov engineers and craftsmen did it. Builders appreciated the quality and affordable price Russian nail plate and there is a steady demand for it. However, for wooden structures big size plates with a low tooth are not enough.
Therefore, at the beginning of May, in addition to the existing line of GP nail plate (tooth height 8.5 mm), Steelcap began production of high-tooth MZP.
This product is an analogue of the European T150 nail plate and the domestic MZP-1.2, made of galvanized steel 1.2 mm thick and has a tooth height of 14 mm. Plate width 124, 145, 176 and 206 mm. Length from 204 to 1250 mm. The difference in size compared to the GNA20 plate is clearly visible in the photo. The use of such fasteners is advisable in critical nodes or with a significant difference in the thickness of the parts to be joined.
At the moment, the first stage of production has been launched, which involves the use of manual labor in some operations. Because of this, performance is still low. But work is underway to complete the fully automated CNC line, which will be launched this quarter. After launch full cycle production, the new nail plate will be available in any size and quantity.
Metal gear plates (MZP)- these are steel elements with a thickness of 1 ... 2 mm, which are obtained by stamping and have working side sharp metal teeth different shapes and length,
each of which has its own functional purpose, photo 1. MZP, due to its teeth, their shape, angle of inclination and location, provide high strength fastening with wood.
MZP - the use of plates, their varieties and characteristics, installation
Photo 1. Metal-toothed plates
MZP are intended for the device of roofing and other designs from wood. MW have optimal thickness, shape and number of teeth for the construction of structures with such spans:
- up to 12 m - truss trusses, interfloor trusses;
- up to 30 m - arched and frame structures;
- up to 10 m - beams.
You should be aware that, in general, designs using MZP are carried out in industrial conditions. This is especially true for structures such as:
- Wall panels;
- floor beams;
- cover farms.
This is due to the fact that in production it is possible to easily fix structural elements in the exact design position, and allows robots to perform with high precision(±10mm) and quality. Photo 2 shows the structural units with the use of MZP.
Photo 2. Units and structures using MZP
For precise fixation of structural elements at the enterprise, it is necessary to use the following equipment:
- hanging press bracket with conductor;
- mobile press;
- stationary press.
Metal-toothed plates are made of galvanized cold-rolled steel. The steel has a zinc coating with a thickness of 14…17 microns.
Metal-toothed elements are used not only in industrial housing construction, but also in private. Also, with the help of MZP, you can perform a device wooden formwork and manufacturing of packaging.
The main types of MZP are divided depending on their thickness, and the thickness determines the width of the plate and its area of application with different cross-sections of beams. Most manufacturers produce MZP of three thicknesses: 1; 1.2; 2 mm, tab. 1. Below are their main parameters.
Table 1
Types of MW
|
Position |
MZP-1.0 |
MZP-1,2 |
|
|
Purpose |
For joining elements up to 38 mm thick |
For joining elements up to 60 mm thick |
|
|
Material |
Cink Steel |
Cink Steel |
|
|
Plate thickness |
|||
|
Plate Width |
|||
|
Insert length |
Any length divisible by 25 mm starting from 50 mm (according to the customer's request) |
||
|
Additional insert sizes |
|
||
|
Tooth height |
|||
There are MZPs that can be used to connect wooden beams with a thickness of 70 mm or more. Manufacturers offer the following plates depending on their thickness:
BUT) with a thickness of 1.2 mm:
- length - 160 ... 340 mm;
- width - 80 ... 140 mm;
- teeth length - 14.8 mm.
B) with a thickness of 2.0 mm:
- length 160…400 mm;
- width 80…200 mm;
- the length of the teeth is 23.5 mm.
Depending on the country of the manufacturer, the minimum wage may differ:
- according to the material of manufacture;
- according to the shape and number of teeth;
- plate thickness.
In the elements of the MZP, the teeth are located very often in order to ensure that the wood works for crushing, and not for chipping. Density of teeth can reach 70 pcs/dm 2 .
MZP are produced with:
- unidirectional arrangement of teeth (Russia);
- bidirectional arrangement of teeth (Poland, Finland, Germany).
The most common design of MZP inserts with unidirectional teeth is a slight offset of adjacent longitudinal rows relative to each other. The main disadvantage of plates with unidirectional teeth is the different strength and deformability of the teeth, the value of which depends on the angle between the axis of the plate and the axis of the force, as well as the angle of direction of the wood fibers to the axis of the force. However, there is a more improved design of the MZP, in which the teeth have a different direction - parallel to the sides and diagonals of the square (it turns out a "herringbone").
The most common MZP in the construction market are the following types (systems):
- Gang Neil (Europe);
- MZP-1.0; MZP-1,2 and MZP-2 (CIS countries);
- Arpad (Hungary).
System feature Arpad is the arrangement of teeth in rows with different angle, directed towards each other, that when pressed into wood, they are jammed and the overall strength of the joint increases.
The most effective are the types of MZP Gang Neil and Arpad, however, every year the design of metal-toothed plates is being improved more and more by leading manufacturers.
The main characteristics of the MZP are given in tab. 2, 3.
table 2
The main characteristics of compounds from MZP
|
Designation |
Stress state of connection |
Characteristic angle α, β, γ hail |
Design bearing capacity of connections with type plates |
|
|
MZP-1,2 |
MZP-2 |
|||
|
R (MPa) working area of the joint |
Crushing of wood bending of the teeth at angles between the direction of the fibers and the acting force β |
|||
|
Rp (kN / m) of the width of the working section of the plate |
Tension of the plate at the angle between the longitudinal axis of the plates and the acting force α |
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|
Rav (kN/m) length of cut section of the plate |
Plate shear at the angle between the longitudinal axis of the plate and the direction of the shear force γ |
|||
Table 3
Estimated bearing capacity of the MZP
|
Type of stress state |
MZP thickness, mm |
Design bearing capacity R (kg/cm) at angle α in degrees |
|||||
|
stretching |
|||||||
Installation of MZP plates
For one simple connection two plates are required - one on each side. To obtain a connection with high strength, it is necessary to use a special press that fixes the exact position of the plates and ensures the required speed of pressing the teeth into the wood.
As noted above, the installation of the MZP and the assembly of the main elements (structures) is carried out in the workshop, and then finished construction transported to construction site, photo 3. The plates should be set so that the rows of teeth are parallel to the wood fibers of the element that takes the most effort.
Photo 3. Manufacturing and installation of wooden structures with MZP
The main advantages of MZP
- Possibility of location of connecting elements in one plane.
- The overall consumption of wood is reduced.
- Relatively low weight of the entire structure.
- The ability to carry out the installation of wooden structures without the use of special lifting equipment.
- Relatively low labor intensity installation work. Works on the arrangement of grooves and spikes in the elements are excluded.
- Reduction of financial costs during the transportation and installation of wooden structures.
- High durability of MZP elements and structures with their application.
- Connections are obtained with relatively high strength compared to adhesive and nail joints.
- The optimal number of people for the construction of wooden structures with a minimum wage is 4 ... 5 people.
- Possibility of the device of wooden designs of any complexity.
- There is software that allows you to speed up the process of designing wooden structures, eliminating the possibility of gross errors in calculating the strength of joints and selecting the desired section of composite beams.
Photo 4. The main advantages of the minimum wage
The main disadvantages of the MZP
- For the manufacture of wooden structures with MZP, a perfectly flat area is required.
- The need for special equipment for the press, which provides the maximum and required strength of the connection. Manual installation MZP (pressing) is not recommended, as it significantly reduces the strength of the connection. The technology of construction of wooden structures with the use of MZP is not widely used in private housing construction, as it requires the use of special equipment and is almost always performed in an industrial workshop.
- Since the MZP of the Gang-Neil system is mainly used, one of the main disadvantages is miscellaneous work plate and his teeth in different directions.
- Under the action of a load on the plate along the main axis, its bending strength of the spikes will be minimal.
- The weak point of the teeth of the plates at the base, where minimum value bending stiffness.
Konev Alexander Anatolievich
