ASTM A490 and ASTM A490M are ASTM International standards for heavy hex structural bolts made from alloy steel. The imperial standard is officially titled Standard Specification for Structural Bolts, Alloy Steel, Heat Treated, 150 ksi Minimum Tensile Strength, while the metric standard (M) is titled Standard Specification for High-Strength Steel Bolts, Classes 10.9 and 10.9.3, for Structural Steel Joints.[1][2]
In 2016, specifications A325 and A490 were officially withdrawn by ASTM and replaced by ASTM F3125. A325 and A490 heavy hex structural bolts are now grades under the new F3125 specification.[3]