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What Are The Classification Of Screws?
Aug 18, 2018

What are the classification of screws?

The main classification of screws includes ordinary screws, machine screws, self-tapping screws and expansion screws.

Cap screw Cap screw used to be limited to full-tooth fasteners.

Hex Head Screws Hex Head Screws and Large Hex Bolt Hex Bolts As the name implies, the head is a hexagonal external thread fastener designed to be rotated with a wrench. According to ASME B18.2.1, hexagon head screws (hex cap screws) have smaller head height and rod length tolerance than conventional Hex bolts, so ASME B18.2.1 hex screws are suitable for mounting on all hex bolts. The place to use also contains large hex bolts that are too large to be used.

Hexagon head cap screw cap screw, also known as a socket head screw or a screw with a hexagonal inner hole in the head, can be tightened or loosened by inserting a hexagonal ruler (hex wrench, hex key or hex key) into the inner hole. . Hexagon socket head screws are most commonly used with cylindrical head screws. The head diameter is about 1.5 times the main diameter of the thread (1960 series). Other head types include semi-circular head screws (bottom cap screws) that make the surface beautiful, and are suitable for tapered screw holes. Flat head screws (counter head screws). Counterbore design allows screw heads not required

It is also possible to be exposed on the surface of the object to be fixed, so it is often used where the surface is small and the traditional wrench is inconvenient to use.

Machine screw machine screws are generally smaller than ¼ inch screws (4#~12#), usually full teeth and rotated by a screwdriver, such as slotted, cross or hexagonal.

Wood screws, machine screws; but according to different purposes can also be divided into many categories; machine screws, can be divided into vertical fastening screws and lateral expansion screws; according to the thread can also be divided into:

A: Triangular thread (60 degrees): bonding / locking / expansion

B: triangular thread for pipe (55 degrees): combined / locked 3)

C: trapezoidal thread (30 or 29 degrees): power transmission

D: square thread (90 degrees): power transmission

stainless steel screw

Machine (tread) car screw, shaft motorbike or bicycle screw and shaft

Stainless steel screw

Stainless steel screw

Screw for needle car, screw for shaft and shaft for sewing

Stop screw sleeve fixing screw

Stainless steel wide tooth screw stainless steel thick thread screw

Stainless steel high and low teeth screw stainless steel high and low threaded screws

Stainless steel machine screw stainless steel machine screw

Stainless steel self-drilling screw

Stainless steel self-tapping screws stainless steel self-tapping screws

Stainless steel self-shaving screw stainless steel thread cutting screw

Stainless steel triangle screw stainless steel trefoil screw

Model Description

P means that the head type is a PAN head; A means a pointed tail tooth, and B means a flat tail tooth, that is, a PA round tipped steel tooth, and a PB round flat mouth steel tooth.

Self-tapping class:

◆ Round head self tapping screw PA

◆ Round head flat tail self-tapping screws PB

◆ Round head cutting self-tapping screws PT

◆ Round head with self-tapping screws PWA

◆ Round head with a flat tail self-tapping PWB

◆ Round head with cutting tail self-tapping PWT

◆Sink head self-tapping screw KA

◆Shentou Pingwei self-tapping screws KB

◆Sink head cutting self-tapping screw KT

◆Half countersunk head tapping screw OA

◆Big head self-tapping screws BA

◆Big head flat tail self-tapping screws BB

◆Big flat head self tapping screw TA

◆ Large flat head flat tail self-tapping screws TB

◆ Large flat head cutting self-tapping screws TT

◆Thin head self tapping screw CA

◆Thin head flat tail self tapping screw CB

◆ Cup head hex self-tapping HA

◆ dry wall nail / wall nail / fiber nail

Machine wire type:

◆ Round head machine screw PM

◆ Round head with machine screw screw PWM

◆Big flat head machine screwTM

◆Sunk head machine screw KM

◆Half countersunk head screw OM

◆Big head machine screw BM

◆Thin head machine screw CM

◆ Cup head tooth bolt HM

Shaoxing Yofa Hardware Co.,Ltd

Address: Room B709,Modern Building,Shaoxing,Zhejiang,China 

Tel: +86-575-85225608

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Fax: +86-575-85228925

E-mail: sales@yofahardware.com