This specification covers the chemical and mechanical requirements of various types of quenched and tempered steel bolts commonly known as “hign-strength structural bolts,” intended for use in structural joints that are covered under requirements of the Specifications for Structural Joints Using ASTM A325 or A490 Bolts, issued by the Research Council on Structural Connections of the Engineering Foundation. The various types of bolts covered in this specification are:
1) Type 1 – Bolts made of medium-carbon steel, supplied in size 1/2 to 1-1/2in., inclusive, in diameter.
2) Type 2 – Bolts made from what is generally described as low-carbon martensite steel, supplied in size 1/2 to 1-1/2 in., inclusive, in diameter.
3) Type 3 – Bolts, 1/2 to 1-1/2 in., inclusive, in diameter having atmospheric corrosion resistance and weathering characteristics comparable to that of the steel covered in Specification A588, Specification A242, and Specification A709 (these steels have atmospheric corrosion resistance approximately two times that of carbon structural steel with copper).
When the bolt type is not specified, either Type 1 or Type 2 may be supplied at the option of the manufacturer. Type 3 bolts may be supplied by the manufacturer if agreed by the purchaser. Where elevated temperature applications are involved, Type 1 bolts shall be specified by the purchaser on the order.
When atmospheric corrosion resistance is required, Type 3 bolts shall be specified by the purchaser in any inquiry or order.
NOTE 1 – Bolts for general applications, including anchor bolts, are covered by ASTM Specification A449, for Quenched and Tempered Steel Bolts and Studs, Also refer to Specification A449 for quenched and tempered steel bolts and studs with diameters greater than 1-1/2 in., but with similar mechanical properties.
This specification provides that heavy hex structural bolts shall be furnished unless other dimensional requirements are stipulated in the purchase inquiry and order.
When galvanized hign-strength structural bolts are specified, the bolts shall be either Type 1 or 2, at the manufacturer’s option, unless otherwise ordered by the purchaser. Bolts shall be hot-dip galvanized, or, with the approval of the purchaser, bolts may be mechanically galvanized. Galvanized bolts and nuts shall be shipped in the same container.
Suitable nuts are covered in Specification A563. Unless otherwise specified, nuts shall be heavy hex.
Grades 2 and 2H nuts, as specifed in Specification A194, and Grades D and DH nuts, as specified in Specification A194, are acceptable alternatives for Grade DH nuts. Type DH3 nuts are acceptable alternatives for C3 nuts.
Unless otherwise specified, washers ordered with the bolts shall be furnished to the requirements of Specification F436. Unless otherwise specified, galvanized washers shall be furnished when galvanized bolts are specified, and Type 3 weathering steel washers shall be furnished when Type 3 bolts are specified.
NOTE 2 – A complete metric companion to Specification A325 has been developed – Specification A325M; therefore no metric equivalents are presented in this specification.
