1. Material: carbon steel, alloy steel, stainless steel & brass steel.
2. Grade: 4.6, 5, 5.8, 8, 8.8, 10.9, 12.9, A2, A4, B7, B7M, L7, L7M, B8, B8M.
1. Diameter: (1) With head - 1/4"~ 3"(M6 ~ M80). (2) Without head - 1/4"~ 6"(M6 ~ M160).
2. Length: no limited under M36.