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Common Specifications For Bolts
- Jul 30, 2018 -

A: Metric Screws B: American rules screws C: inch screws

A: Metric Mechanical Screws: Metric

EX:M3 x 6–p P b:m3 mechanical screws, 6mm long, cross, round flat head, plated black.

Finish Code: Appearance processing specifications

Head Code: Header shape

Thread Code

Screw model Drive Code: Head trench, feature model

Length Code: Screw lengths (mm)

A-1: Thread Code: Screw model

Metric screws directly to the screw outside diameter to mark the screw model, such as M3 is the diameter of the screw 3.00mm.

M4 the screw diameter is 4.00mm.

Metric Thread Size x Pitch:

Note: The metric screws are in the rear of the screw model, sometimes indicating the screw spacing.

such as m3x0.5,m4x0.70,m5x0.8,m6x1.

But because of the standard norm, usually does not mention.

A-2: Length Code: Screw Lengths:

Metric screws, which directly indicate the length of the screws, mm in units.

The total length of the screws is indicated, only the length below the head is calculated, excluding the height of the head.

With the exception of the flat head screws, the total length of the screws is marked with the height of the skull.

A-3: Drive code/The head of the ditch, features.

Common categories

A. Slotted: one word (minus)

All kinds of common screws

All kinds of common screws (20 pieces)

B. Phillips: Cross (Plus)

C. phil-slot: one word/Cross

D. Hex Socket: Hexagon

E. One Way: One-way (only lock, can not exit)

A-4: Head code/shape.

A. Flat: Flat head (after locking, top and work piece flush)

B. Oval: Salad head, O-head, semi-sunken head

C. Round: Round Head

Screw metering Unit

Screw metering Unit

D. Pan: Round flat head

E. Truss: Large round flat head

F. Hex: Hexagon head.

A-5: Finish code/appearance processing.

Metric Self tapping Screws: tapping Type is directly marked after the name.

EX:M3 x 6–ppb,tapping 


M3 self tapping screws, 6mm long, cross, round flat head, plated black. Generally to product or mark, and then judged as sheet Metal or plastic parts used.