The ASTM A325 is a type of high-strength heavy hex structural bolt with diameters ranging from 0.5 inches to 1.5 inches. They possess a shorter thread length than standard hex bolts, since they are manufactured for use in structural connections. In contrast, for those who wish for bolts for general applications, such as anchor bolts, Specification A449 bolts are more suitable.
The ASTM A325 heavy hex structural bolts were manufactured in three types: Type 1, which are medium carbon, carbon boron or medium carbon alloy steel; Type 2, which was withdrawn in November 1991; and Type 3, which is made from weathering steel. In addition, there was a type T manufactured that is a fully threaded version of the A325, restricted to four times its diameter in length, and the type M, which is a metric version of the A325.
The ASTM A325 structural bolt possesses three types of connections: SC, a slip critical connection; N, a bearing type connection with threads included in the shear plane; and X, a bearing type connection with threads excluded from the shear plane.
ASTM A325 structural bolts can come with two different mechanical specifications. The first can be between 0.5 inches and 1 inch, have tensile ksi of 120 min, a yield ksi of 92 min, an elongation percentage per minute of 14 percent, and an RA percentage per minute of 35 percent. The second type possesses a size between 1.125 inches and 1.5 inches, has tensile ksi of 105 min, a yield ksi of 81 min, an elongation percentage per minute of 14 percent, and an RA percentage per minute of 35 percent.
For Type 1 A325 structural bolts, the recommended complementary nuts are: A563C, C3, D, DH, DH3 plain types and A563DH galvanized types. The complementary washers are F436-1. Type 3 A325 structural bolts can be paired with both A563C3 and DH3 plain nuts. The compatible washers for Type 3 bolts are F436-3 types. In addition, the nuts that conform to the A194 Grade 2H can be used as a suitable substitute for use with the ATSM A325 structural bolts.
