This specification covers two types of heat treated, steel, tension control bolt-nut-washer assemblies, also referred to as "sets," having a tensile strength of 150 to 173 ksi. These assemblies are capable of developing a minimum predetermined tension when installed by applying torque to the nut, while at the same time applying a counter torque to separate the spline end from the body of the bolt using an appropriate spline drive installation tool. The tension control bolts are designated by type denoting chemical composition as follows: type 1 - alloy steel, and type 3 - weathering steel. The chemical composition of the tension control bolts, nuts, and washers shall conform to the requirements specified. The assembly lot tension test shall be performed on fastener assemblies to determine the ability of the assembly to provide the required minimum tension. Tensile strength, proof load, hardness, and carburization/decarburization shall be tested to meet the requirements prescribed.

1.1 This specification covers two types of heattreated, steel, tension control bolt-nut-washer assemblies, alsoreferred to as “sets,” having a tensile strength of 150 to 173 ksi.These assemblies are capable of developing a minimum predeterminedtension when installed by applying torque to the nut, while at thesame time applying a counter torque to separate the spline end fromthe body of the bolt using an appropriate spline drive installationtool.

1.2 An assembly consists of a tension control boltwith spline end (covered by this specification) and a suitable nutand washer covered by reference to applicable ASTMspecifications.

1.3 The fastener assemblies are intended for use instructural connections. These connections, installation procedures,and the use of alternate design structural bolts are covered underthe requirements of the “Specificationfor Structural Joints Using ASTM or A490 Bolts”, approved by theResearch Council on Structural Connections.

1.4 The assemblies are available with either round(button or dome) heads, heavy hex structural heads, or alternatedesign heads described in Section 11 , in sizes ½ to 1 ¹/₈in. inclusive, in two types specified in Section 4.

1.5 Tension control bolts manufactured and marked inaccordance with the requirements of Specification A490, and conforming to the dimensional and other requirementsof this specification, will be considered an acceptable alternateunder this specification for two years following initialpublication.

1.6 The following precautionarystatement pertains only to the test method portions, Sections 15and 16, of this Specification: This standard does not purport toaddress all of the safety concerns, if any, associated with itsuse. It is the responsibility of the user of this standard toestablish appropriate safety and health practices and determine theapplicability of regulatory limitations prior to use.