Common Standards And Classification Of Cold Heading Steel-CBIES Fasteners

The main manufacturing techniques of fasteners are cold heading (bolts, nuts and other products) and stamping (reed-type fasteners and gaskets, etc.)

 

1. Common standard for cold heading steel

ISO 4954:2021(en), Steels for cold heading and cold extruding

GB /T 6478 - 2015, Steels For Cold Heading And Cold Extruding

 

GB/T28906  GB/T5953    Q/BQB517

JIS G3507   JIS G4051   JIS G4053

SAE J403    SAE J404   SAE J404    DIN 1654

 

2. According to GB/T6478-2015 "Steel for Cold Heading and Cold Extrusion", and in accordance with international standards and domestic general rules, there are four types of cold heading steel by heat treatment:

1). Non-heat treatment type: the cold heading of the fastener does not need heat treatment after forming. The finished product grade is 4.66.8.

2). Surface hardening type: after cold heading forming of fasteners, the surface carburizing (nitriding) treatment is required, and then quenching and low-temperature tempering treatment is carried out. The finished products are mainly self-tapping screws and self-drilling screws.

3). Quenching and tempering type (including boron-containing steel): after cold heading forming of fasteners, normalize and then quench with high-temperature tempering, or directly quench with high-temperature tempering. The grade of finished products processed is 8.812.9.

4). Non-quenching and tempering type: do not need quenching and tempering heat treatment, add trace alloy elements in the steel, so that it has good comprehensive mechanical properties in the rolling or forging state, so as to reduce the quenching and tempering process. GB/T3098.22 Bolts, screws, and studs of fine-grain non-quenched and tempered steel -- Machine Class 8.8F-10.f