1. Standard: DIN, ANSI, GB and non-standard;

2. Thread: machine, self-tapping, or self-drilling; full thread or half;

3. Surface: full shape, no burr and nice flatness;

4. Raw Material: bought from Group Company, 100 tons per batch, with stable quality and completive price;

5. Processing: by cold-forging machines, together with precise moulds and punch pins;

6. Length: various