1.1 This specification covers the chemical and mechanical requirements of quenched and tempered steel bolts, in nominal thread diameters M16 to M36, inch. These bolts are intended for use in structural joints that are comparable to those made under the Specification for Structural Joints Using ASTM A 325 or A 490 Bolts issued by the Research Council on Structural Connections of the Engineering Foundation. The various types of bolts covered by this specification are:
1.1.1 Type 1- Bolts made of alloy steel, supplied in nominal thread diameters M16 to M36, inclusive.
1.1.2 Type 2-Bolls made from what is generally described as low-carbon martensite steel, supplied in nominal thread
diameters M16 to M24 inclusive.
1.1.3 Type 3-Bolts in nominal thread diameters M16 to M36, inclusive, having atmospheric corrosion resistance and
weathering characteristics comparable to that of the steels covered in Specifications A 588/A 588M, A 242/A 242M, and A 709/A 709M. The atmospheric corrosion resistance of these steels is substantially better than that of carbon steel with or without copper addition. See 6.3. When properly exposed to the atmosphere, these steels can be used bare (uncoated) for many applications.