The parameters that need to be indicated for the description of the fastener are: product name (standard), specification, material, strength grade, surface treatment. Such as: DIN912, M4-0.7x8, SCM435, 12.9, black.
1.product name (standard)
Note: For screws without standard, if it is non-standard, you need to provide drawings.
For example, DIN912, the Chinese name is: Hexagon socket head screw, this is the name of the product.
However, the most accurate method is still to call the standard, because GB70 is also the same name; but the two standards have many different sizes.
The most influential standards in the world are: German Standard (DIN), International Standard (ISO), Chinese National Standard (GB), American Standard (ANSI), and Japanese Standard (JIS).
2.specifications
Generally, the screw is called the tooth scale diameter * screw length.
The horn pattern is commonly used in the metric system: M2, M3, M4, M5, M6, M8, M10, M12, etc.
Commonly used in the US system are: 4#-40,6#-32,8#-32,10#-24,1/4-20,5/16-18,3/8-16, 1/2-13, etc.
The length of the screw refers to the effective length of the embedded object. For example, the countersunk screw is loaded with the total length, the half countersunk screw is added with the length of the half head, and the cylindrical head screw length does not include the head size. Such as:
For the specification, the full name is best added with the tooth distance. For example, M4-0.7x8, 4 finger outer diameter is 4mm, 0.7 means that the distance between the two tooth peaks is 0.7mm, and 8 means that the effective length of the embedded object is 8mm.
For the sake of simplicity, without writing the tooth pitch, we defaulted the coarse tooth to the standard tooth because it is the most common; this way it is not marked. This is only the metric system, and the American products still have to be marked.
