Metal toothed plates (MTP)– these are steel elements 1...2 mm thick, which are obtained by stamping and have sharp metal teeth on the working side different shapes and lengths
each of which has its own functional purpose, photo 1. MZP, thanks to its teeth, their shape, angle of inclination and location, provide high strength of fastening to wood.
MZP - application of plates, their types and characteristics, installation
Photo 1. Metal toothed plates
MZP are intended for the installation of roofing and other structures made of wood. minimum wages have optimal thickness, shape and number of teeth for the construction of structures with the following spans:
- up to 12 m – rafter trusses, interfloor trusses;
- up to 30 m – arched and frame structures;
- up to 10 m – beams.
You should know that basically designs using MZP are carried out in industrial conditions. This is especially true for such structures as:
- Wall panels;
- floor beams;
- covering trusses.
This is explained by 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 accuracy (±10mm) and quality. Photo 2 shows the design components using MZP.
Photo 2. Assemblies and structures using MZP
To accurately fix 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 ones. Also, with the help of MZP it is possible to install wooden formwork and manufacture packaging containers.
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 sections beams. Most manufacturers produce MZP of three thicknesses: 1; 1.2; 2 mm, tab. 1. Below are their main parameters.
Table 1
Types of minimum wages
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Position |
MZP-1.0 |
MZP-1,2 |
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Purpose |
For connecting elements up to 38 mm thick |
For connecting elements up to 60 mm thick |
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Material |
Cink Steel |
Cink Steel |
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Plate thickness |
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Plate width |
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Plate length |
Any length multiple of 25 mm starting from 50 mm (at customer’s request) |
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Additional plate sizes |
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Tooth height |
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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:
A) 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;
- teeth length - 23.5 mm.
Depending on the country of manufacture, minimum wages may differ:
- according to the material of manufacture;
- by shape and number of teeth;
- plate thickness.
In MZP elements, the teeth are located very often to ensure that the wood works for crushing and not for chipping. The density of teeth can reach 70 pcs/dm2.
Minimum wages are produced with:
- unidirectional arrangement of teeth (Russia);
- bidirectional arrangement of teeth (Poland, Finland, Germany).
The most common design of MZP plates with unidirectional teeth is a slight shift 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 different direction– parallel to the sides and diagonals of the square (it turns out to be a “herringbone”).
The most common minimum wages in the construction market are the following types (systems):
- Ganges Neil (Europe);
- MZP-1.0; MZP-1,2 and MZP-2 (CIS countries);
- Arpad (Hungary).
Feature of the system Arpad is the arrangement of teeth in rows with different angles, directed towards each other, so that when pressed into wood, they become jammed and the overall strength of the connection increases.
The types of minimum wages considered to be the most effective Gang Neil And Arpad, however, every year the design of metal toothed plates is increasingly improved by leading manufacturers.
The main characteristics of the MW are given in table 2, 3.
table 2
Main characteristics of connections from MZP
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Designation |
Stressed state of connection |
Characteristic angle α, β, γ hail |
Design load-bearing capacity of connections with type plates |
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MZP-1,2 |
MZP-2 |
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R (MPa) working area of connection |
Wood crushing and bending of teeth at angles between the direction of the fibers and the acting force β |
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Rр (kN/m) 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 the cut section of the plate |
Shear of the plate at the angle between the longitudinal axis of the plate and the direction of the shear force γ |
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Table 3
Design load-bearing capacity of MZP
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Type of stress state |
MZP thickness, mm |
Design load-bearing capacity R (kg/cm) at angle α in degrees |
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Stretching |
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Installation of MZP plates
For one simple connection two plates are needed - 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 minimum wages and the assembly of the main elements (structures) is carried out in the workshop, and then finished design transported to the construction site, photo 3. The plates should be placed so that the rows of teeth are parallel to the grain of the wood of the element that absorbs high forces.
Photo 3. Manufacturing and installation of wooden structures with minimum wages
The main advantages of the minimum wage
- Possibility of arrangement of connecting elements in one plane.
- The overall wood consumption is reduced.
- Relatively low weight of the entire structure.
- The ability to install wooden structures without the use of special lifting equipment.
- Relatively low labor intensity installation work. Work on the installation of grooves and tenons in the elements is excluded.
- Decline financial expenses when transporting and installing wooden structures.
- High durability of MZP elements and structures using them.
- The joints are relatively strong compared to adhesive and nail joints.
- The optimal number of people for the construction of wooden structures with minimum wage is 4...5 people.
- Possibility of constructing wooden structures of any complexity.
- Exists software, which allows you to speed up the process of designing wooden structures, eliminating the possibility of making gross errors in calculating the strength of connections and selection the required section composite beams.
Photo 4. Main advantages of minimum wage
Main disadvantages of minimum wage
- For the manufacture of wooden structures with MZP, a perfectly flat platform is required.
- The need for special press equipment that provides the maximum and required joint strength. Manual installation MZP (press-fitting) is not recommended, as it significantly reduces the strength of the connection. The technology for constructing wooden structures using MZP has not become widespread in private housing construction, since it requires the use of special equipment and is almost always carried out in an industrial workshop.
- Since the Gang-Neil systems are mainly used, one of the main disadvantages is miscellaneous work plate and his teeth in different directions.
- When a load is applied to the plate along the main axis, its bending strength of the tenons will be minimal.
- The weak point of the teeth of the plates is at the base, where the bending rigidity is minimal.
Konev Alexander Anatolievich
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 reproduce such a product, but Kirov engineers and craftsmen managed it. The builders appreciated the quality and affordable price Russian nail plate and there was a steady demand for it. However, for wooden structures big size Low tooth plates are not enough.
Therefore, at the beginning of May, in addition to the existing line of GP nail plate (8.5 mm tooth height), Steelcap began production of high tooth nail plates.
This product is an analogue of the European nail plate T150 and the domestic MZP-1.2, made of galvanized steel 1.2 mm thick and has a tooth height of 14 mm. Plate widths are 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 units or when there is a significant difference in the thickness of the parts being connected.
At the moment, the first stage of production has been launched, which involves the use of manual labor in some operations. Because of this, productivity is still low. But work is underway to complete a fully automated CNC line, which will be launched this quarter. Once the full production cycle is launched, the new nail plate will be available in any size and quantity.
It is used for fastening the rafter part of the house, as well as for connections in frame housing construction. It is a strip (plate) made from galvanized steel sheet with stamped nails (teeth). Production of nail plates using the cold stamping on a hydraulic press allows you to obtain high-quality connecting elements. Standard insert teeth are 8 millimeters high. One nail plate can have from 2 to 16 rows of teeth.
The thickness of the nail plate is from 1 millimeter, the width can be, depending on the standard size, from 20 to 132 millimeters, and the length can be from 76 to 1250 millimeters. With the help of metal toothed connecting plates, wooden structural elements such as boards, beams, beams lying in the same plane can be connected without the use of nails, screws and other fasteners.
Why fastening can be a problem
The issue of fastening is very important due to the characteristics of wood, its “behavior” depending on weather conditions. With changes in the degree of humidity, wooden building elements decrease or increase in size and are often subject to bending. As a result, large and long-term “stresses” arise in the places of their connections and abutments. The reason for this may also be the construction of a light foundation or its complete absence (which is possible given the low weight and elasticity of wooden structures), leading to a change in the geometry of these structures.
When using a metal plate, increased corrosion resistance of the connecting element is ensured, which favors its operation in conditions high humidity, as well as when performing external work.
Properties of nail plate
The connecting nail (toothed) plate has important advantages compared to other types of fastenings. For example, from separately driven nails, each of which is on its own.
- The strength of the bond to wood is achieved by the shape of the teeth, their angle of inclination, and their arrangement in rows. At the junction of wooden structural elements, the nail plate forms a connection that has high strength characteristics that no other fastening element can compete with. These indicators have been verified by many mechanical tests of structures.
- A common monolithic platform - the base on which all the teeth are attached, eliminates the possibility of their mobility and swinging. The platform becomes common, binding basis for the connected parts of the structure, due to which the connection is again given the quality of strength.
- Metal serrated plates provide excellent strength even when joining wood structural elements by butt connection.
- The parts are attached extremely tightly. This has also been proven experimentally. For example, a beam assembled using a plate of two butt-joined wooden beams, when exposed to a fracture, it broke not at the junction of the structural elements, but in the monolithic part of the beam. Thus, the monolithic nail plate platform completely prevents the teeth from moving or becoming loose and becomes reliable basis connecting node.
- If necessary, it can be applied electroplating- this is possible additional service at the request of the customer. This coating will give additional durability to the steel nail plate.
- Metal toothed plates install faster than traditional types fasteners, thanks to the unique design. This will significantly save time during construction and installation work on fastening rafter and underframe elements. rafter systems.
- Due to the possibility of manufacturing floor beams with “corridors” specially designed for these purposes, this fastening method facilitates the laying of communications (ventilation ducts).
Experience in using nail plates
Steel nail plates have been used for more than twenty years in Canada and the USA, namely in North America They began to be widely used in the construction of wooden structures. This fastening method is now widely used throughout Europe. With the help of industrially produced truss structures based on plates, you can build almost any type of roof, attic, attic spaces, skylights, etc.
Roofs using nail plates are applicable in all types of structures, for example:
- residential buildings,
- industrial,
- agricultural,
- sports and commercial facilities.
- reconstruction of buildings and flat roofs, where plates are considered an indispensable type of fastener;
- production of wall panels;
- production of lattice frames,
- construction of formwork for concrete structures,
- construction of long-span premises made entirely of wood.
Tooth (nail) plate is a strong, fast and economical connection for wooden structures. Distinctive Advantages and the properties of this fastening contribute to its increasingly widespread use in construction wooden houses and structures in our country. The opportunity to purchase these products is becoming more and more accessible, and those interested can evaluate the convenience and quality of this fastener in practice.
Construction frame houses is gaining popularity: they are relatively cheap and comfortable. In classic designs of houses and structures made of stone, brick and other materials, rafter systems are made of wooden elements, so the issue of reliable connection of beams, timber or other wooden elements is constantly relevant. Recently, the nail plate has been widely used - a new product among fasteners, which has successfully replaced nails, dowels and screws.
Design and material of manufacture
From the name it is clear that the design of a nail plate is a strip of metal with an analogue of nails. Its thickness ranges from 1 to 2 mm, dimensions vary from 40 to 200 mm in width, and the length can be any. U different manufacturers your size standards. Most often, nail plates are produced in length increments of 25 mm.
Source material for production is high-strength sheet alloy or galvanized steel. In production, it is cut into plates of the required size, and then thin protrusions up to 8 mm long are extruded using a special press. They play the role of nails, firmly entering wooden structures.
Application area
Any wooden structures that are connected to each other must have an overall rigidity to maintain bearing capacity and preventing deformation of the entire structure. The fastener that best copes with this task is nail plates. They are used in residential, public, and industrial construction in the construction of frame wooden structures and installation of rafter systems.
Methods of use
Production wall panels, or arches carried out in production workshops. The structural elements are fixed in jigs or other devices and connected with a nail plate using a press. This connection method is of the highest quality, but it is not always possible to use it.
It is not possible to use nail plates using a press on a construction site. They are simply driven in with a hammer and at the same time ensuring that the protrusions fit evenly into the wood.
Main advantages
The popularity of nail plates is due to their advantages over other types of fasteners:
- the ability to connect elements in one plane without significant protrusions on the surface;
- low dead weight, which reduces the overall weight of the structure;
- the use of nail plates makes it possible to mount complex systems gradually without the use of heavy construction equipment;
- reduction in the total cost of the constructed facility (prices are quite high, but the fasteners in question are relatively inexpensive);
- the use of a plate increases the rigidity and strength of joints in composite structures;
- Installation of a nail plate is quite simple and does not require specialized knowledge.
Existing disadvantages
This type fasteners are not without their disadvantages, of which the most significant are the following:
- low strength and rigidity under bending loads at the joint;
- manual installation of nail plates does not always provide maximum rigidity and strength of the connection;
- To obtain a high-quality structure with precise design dimensions, a platform with ideal evenness is required.
Types by tooth arrangement
Manufacturers often try to reduce the price of the building materials they produce. One way to do this is to simplify the design and production technology. Because of this, most of the nail plates used are the simplest and cheapest type with unidirectional teeth. But there are other options that are used in critical designs: with multidirectional teeth in adjacent rows and with teeth located at an angle of 45 degrees to the longitudinal axis of the plate. These options are more difficult to produce, therefore the price of building materials for fastening these types is slightly higher.
Classification and manufacturers
In LNG countries, a classification of MPZ (metal toothed plates - the name of nail plates according to GOST) has been adopted by thickness: MPZ-1.0, MPZ-1.2 and MPZ-2.0 are manufactured with a thickness of 1.0, 1.2 and 2.0 mm, respectively.
IN Western Europe A popular standard is the bi-directional gang-nail toothed key from manufacturing companies in Sweden, Germany, Poland and Finland. In Hungary and neighboring countries, nail plates from the Arpad company are popular, notable for their high strength. The price of one plate, depending on the type, size and manufacturer, ranges from 10 to 120 rubles.
It is a metal plate, on the surface of which there are several rows of spikes made by stamping.
It is they that, when installing this fastening element, “bite” 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 gear plates made of?
Serial production of nail (toothed) plates is carried out on specialized industrial equipment. They are made from galvanized sheet steel.
In the production of this type of fastener, powerful hydraulic presses, characterized by high performance.
This equipment allows you to produce 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.
Fastening plates (toothed) are also used to connect timber, and it turns out to be very strong and durable. This fastener greatly simplifies and speeds up the assembly of lattice frames.
Advantages of tenon mounting plates
Tenon fasteners have gained wide popularity due to the numerous advantages and benefits that their use offers.
The main one is, perhaps, that this fastener guarantees a strong and durable connection wooden parts. In this case, the wood does not split and its integrity is maintained.
Thanks to the presence of a high-quality anti-corrosion coating, the nail plates are virtually rust-free, which is especially important for such a hygroscopic material as wood.