Common specifications of screws


2023-05-29 09:57

A: Metric screw B: American screw C: English screw
A: Metric mechanical screws: Metric
Ex: M3 x 6-P P P B: M3 mechanical screw, 6mm long, cross shaped, round flat head, black plated
Finish Code: Appearance Treatment Specification
Head Code: Head shape.
Screw head shape. Cylindrical head. Half countersunk head. Sink head. Spherical cylindrical head. Pan head. Half round head. Hexagonal head.
Thread Code
Screw model Drive Code: Head groove, feature model
Length Code: Screw length (mm)
A-1: Thread Code: Screw model
Metric screws directly indicate the screw model with the outer diameter of the screw,
For example, M3 refers to a screw with an outer diameter of 3.00mm; M4 refers to a screw with an outer diameter of 4.00mm
Metric Thread Size x Pitch:
Note: Metric screws are sometimes indicated with the screw pitch after the screw model
For example, M3x0.5, M4x0.70, M5x0.8, M6x1
But due to standard specifications, it is usually not mentioned
A-2: Length Code: Screw length:
Metric screw, directly indicating the length of the screw, in millimeters
The total length indication of the screw only calculates the length below the head, excluding the head height
Except for flat head screws, where the total length of the screw includes the height of the head
A-3: Drive Code/Head Trench, Features

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