Marking Methods of Fastener

1.5 Marking Methods of Fastener

1. Referenced Standards

GB/T 1237-2000 "Fastener Marking Methods", GB/T 3099.1-2008 "Fastener Terminology - Threaded Fasteners, Pins and Washers".

2. Complete Marking of a Fastener

According to GB/T 1237-2000, the complete marking of a fastener consists of 11 elements: Category, Standard Number, Thread Size or Nominal Size, Other Diameters or Characteristics, Nominal Length, Thread Length or Shank Length, Product Form, Property Class or Hardness or Material, Product Grade, Drive Type, and Surface Treatment.

Example:
Bolt GB/T 5782-2000 - M12 × 80 - 8.8 - A - zn·D

3. Simplified Marking Principles for Fasteners

The marking of fasteners may be simplified according to the following principles:

1. The fastener name and the year code in the standard number may be omitted.

2. When only one type, precision, property class or material, heat treatment, and surface treatment are specified in the fastener product standard, they may be omitted.

3. When two or more types, precision levels, property classes or materials, heat treatments, and surface treatments are specified in the product standard, one of them may be designated for omission.

Simplified Examples:
Bolt GB/T 5782 - M12 × 80
Nut GB/T 6170 M12 - 10 - O