ASTM A325 and ASTM A490 are the two ASTM standard structural bolt specifications. First, A325 and A490 bolts are produced Alloy Bolt with a heavy hex head configuration which provides a wider bearing surface over which to distribute the load.
ASTM A490 bolts are available in diameters from 1/2 to 1-1/2 inch diameters with a minimum tensile strength of 150,000 PSI for all diameters and are offered in two types. Type 1 is alloy steel, and Type 3 is weathering steel that offers atmospheric corrosion resistance similar to that of ASTM A242 or A588 steels. Type 3 bolts shall be marked "A490".
- Material: SS, Alloy steel & weathering steel
- Diameters: 1/2 to 1-1/2 inch
- Grade: ASTM-A325, A490, A242, A588