1.2.1 Bolts manufactured under this specification, and structural bolting assemblies supplied under this specification, are intended for use in structural connections covered in the Specification for Structural Joints Using High-Strength Bolts and installed using the torque-and-angle or part turn/combined installation method.

1.2.2 Structural bolting assemblies in this specification are furnished in nominal diameters from ¹/₂ to 1-¹/₄ in. inclusive.

1.3.1 Structural bolting assemblies are designated as Grade 144.

1.3.2 Bolts are designated by type denoting raw material chemical composition.

1.4.1 Torque-and-Angle Fixed-Spline Structural Bolt-bolt that includes an integral fixed-spline end which extends beyond the threaded portion of the bolt and is used as a component of a torque-and-angle fixed-spline structural bolting assembly.

1.4.2 Torque-and-Angle Fixed-Spline Structural Bolting Assembly2- a fastener assembly comprised of a torque-and-angle fixed-spline bolt with a suitable nut and at least one washer, installed and tightened using a special electric wrench and socket system which has an inner socket that engages the fixed-spline end of the bolt and with an outer socket that engages and turns the nut, in two separate and distinct operations, the first is a controlled torque application and the second is a specified angle.

1.4.3 Combined Method-A tightening method comprised of two steps, the first tightening step using a torque regulating tool and the second tightening step in which a specified turn is applied to the turned part of the assembly. Also known as the ‘part turn method'.