How many kinds of self tapping screw specifications are there, and what are the specifications and s

How many kinds of specifications of self-tapping screws, there are many specifications of self-tapping screws, it can have different groove types, head types, and different specifications, generally M1-M10 within the screws are more commonly used, and the length is long and short, this is mainly based on the actual use of self-tapping screws to choose the specifications of self-tapping screws, rather than looking at the specifications of self-tapping screws and then choose. The use scenario of screws is different, and naturally its specifications and sizes are not different, and there are also some standard screws, with more specifications and sizes, which can not be explained clearly in a few words, general hardware stores or spot screw factories.

Some specifications will be complete.

1.The self-tapping screw M4 25 expresses the meaning of the standard ordinary round thread, a coarse external thread with a diameter of 4mm, a pitch of 1mm, and a length of 25mm. Refer to the national standard:

GB T 6561-1986 "Cross groove countersunk self-tapping locking screw", this standard specifies the thread specification of the cross groove countersunk self-tapping locking screw.

2.Other specifications and standards for self-tapping screws are:

GB T 5280-2002 "Threads for self-tapping screws" specifies that the thread specification is ST self-tapping screws (screws for sheet metal).

GB T 5285-1985 "Hexagon Head Self-Tapping Screws" This standard specifies the hexagonal head self-tapping screws with thread specifications of ST.

GB T 6563-2014 "Hexagon Head Self-Extrusion Screws" This standard specifies hexagonal head self-extrusion screws with thread specifications of M2 M12. This standard applies to hexagonal head self-extrusion screws.

Countersunk self-tapping screws (diameter length):

4 16 install hinges, feet, supports and other accessories for board installation.

4 30 external door panel or trim plate corner connection.

4 35 external door panel or trim plate corner connection cabinet ordinary hanging code and side panel connection.

4 40 panel furniture does not use the nail connection of eccentric parts, which was not a formal practice in the early days, and is still used by carpenters.

8 60 or 80 cabinet wall cabinet expansion pipe into the wall nails.

Peculiarity. 1. Generally, it is made of carburized steel (accounting for 99% of the total output). It can also be made of stainless steel or non-ferrous metals.

2. The product must be heat treated. Carbon steel self-tapping screws must be carburized, and stainless steel self-tapping screws must be solution hardened. In order to make the self-tapping screws meet the mechanical properties and service performance required by the standard.

3. The surface hardness of the product is high and the core toughness is good. That is, "soft inside and rigid outside". This is a major feature of the performance requirements of self-tapping screws.

If the surface hardness is low, it cannot be screwed into the matrix; If the toughness of the core is poor, it will break as soon as it is twisted, and it cannot be used. Therefore, the "inner flexible outer steel" is a self-tapping screw to meet the very important requirements of the use performance.

Summary. Hello, if it is a standard pitch, the diameter of the hole should be the recommended value: plate thickness bottom hole; Plate Thickness Bottom Hole Plate Thickness Bottom Hole Plate Thickness Bottom Hole. Through my hope it can help you.

Hello, if it is a standard pitch, the diameter of the hole should be the recommended value: plate thickness bottom hole god; Plate Thickness Bottom Hole Plate Thickness Bottom Hole Plate Thickness Bottom Hole. I hope it can help you.

The relationship between the low hole of the self-tapping screw on the plastic and sheet parts and the nominal diameter is: the nominal diameter is minus, and the tightness is adjusted as needed. Such as:

Nominal diameter self-tapping nail hail midsole hole; Nominal diameter self-tapping nail bottom hole potato; Nominal diameter 6 self-tapping nail bottom hole; Nominal diameter 8, self-tapping branches, mountain nails, bottom holes, etc.

There are as many as 13 specifications and models of self-tapping screws on the market, such as T1, and so on. In addition, from the material, shape, use and other aspects can also be divided into ordinary screws, self-cutting and self-tapping or metal drive and other screws, different types of screws use different functions and use objects, use according to the actual needs to choose.

Introduction:

Screw refers to the screw (foreign name: screw), which is a tool that uses the physical and mathematical principles of the oblique circular rotation and friction of the object to tighten the mechanical parts of the object step by step. Screws are a generic term for fasteners, everyday colloquialism.

The metric thread is measured in mm (millimeters), and it has a cusp angle of 60 degrees. Both American and Imperial threads are measured in inches. The cusp angle of the American thread is also 60 degrees, while the cusp angle of the inch thread is 55 degrees.

Due to the different units of measurement, the various threads are represented differently. For example, an example of M16-2x60 represents a metric thread. His specific meaning means that the nominal diameter of the screw is 16mm, the pitch is 2mm, and the length is 60mm

1 4-20x3 4 represents the imperial thread.

He specifically meant that the screw had a nominal diameter of 1 4 inches (one inch =, with 20 teeth on one inch and a length of 3 4 inches. In addition, if you want to represent American screws, you will generally add UNC and UNF after the British screws to distinguish between American coarse teeth and American fine teeth.

Summary. The relationship between the bottom hole of the self-tapping screw on the plastic parts and sheet parts and the nominal diameter is: the nominal diameter is minus, and the tightness is adjusted as needed.

The bottom hole generally refers to the diameter of the prefabricated hole before tapping the internal thread with a tap, and generally refers to the built-in round hole of the workpiece, and the circular hole on the bottom or surface is called the bottom hole.

In the process of tapping threads, the cutting edge is mainly to cut the metal, but there is also the effect of squeezing the metal, thus causing the phenomenon that the metal is convex and flows to the tooth tip, so before tapping, the hole diameter (that is, the bottom hole) should be greater than the inner diameter of the thread.

The basic shape, basic size, tolerance and fit of the thread conform to the provisions of GB196-81 and GB197-81 respectively. This standard is applicable to the connection threads of pipe fittings screwed into the machine body, such as the pipe joints, lubricating parts and instruments of hydraulic parts and pneumatic components, etc., and the sealing structure of end gasket tightening is adopted.

Dear, hello, I am happy to answer for you, the difference between self-tapping screws and pointed screws is wood screws, and self-tapping screws are threads. Self-tapping nails have sharper tips and smaller diameters, making them easy to twist. Wooden screws should be thicker, strong connection force self-tapping screws, everyone has seen, generally fingertip thick teeth and hard texture of wooden screws.

Of course, there are also aluminum alloys; Plastic. A special type of self-tapping screw used for opening threads in metal holes is called tapping. Self-tapping screws are used for non-metallic or soft metals, without priming holes and tapping; The self-tapping screws are pointed, so that they can "self-tap", and ordinary screws are flat-headed, with the same thickness.

The difference between self-tapping screws and flat-head screws is that self-tapping screws do not need to tap the holes, and the screws used are different from the general, the head is pointed, and the tooth spacing is relatively large, which is a bit similar to the chipless tapping, which can be screwed in directly without tapping, and the metal and the plastic usually use this method. The flat-head screws are mostly used in CCB's potato construction sites and other projects, and for power dispatching of power systems in hydroelectric power stations. Self-tapping screws:

Generally, it is a kind of screw with a pointed end, thick teeth, and high hardness, and it is also a flat head and a cross opening. Ordinary screws also have flat heads, with the same thickness up and down, and male and inch threads.

1. What are the specifications of self-tapping screws?

According to the diameter of the screw, there are 13 specifications, respectively, the user needs to decide the specification of the screw according to the actual needs when purchasing. In addition, according to the different shape of the head, self-tapping screws can also be divided into three types: round-head self-tapping screws, flat-head self-tapping screws and countersunk self-tapping screws.

Second, how to choose the right self-tapping screw.

1. Look at the type of screw.

According to professionals, there are many types of screws on the market, and different types of self-tapping screws have very different scopes of application, aesthetics and performance characteristics. For example, if the screws used to fix the aluminum alloy are used, it is generally recommended to use flat-head screws.

2. Look at the size of the screw.

From the above article, it can be understood that there are many specifications and models of screws, and the force capacity of different types of self-tapping screws is very different. In the case of the same force, the longer the screw, the better its ability to hold nails, and the stronger the load-bearing capacity, so consumers must choose according to the design standards when purchasing.

3. Look at the quality of the screws.

There are many channels to buy self-tapping screws, and users must go to regular hardware stores to buy when buying, so as to ensure the quality of self-tapping screws. In addition, when purchasing self-tapping sail screws, it is also necessary to check whether the threads of the screws are clear and whether the size is consistent with the specifications, because this is the key to determining the performance of the screws.