This specification covers the requirements for two types (Types 8.8 and 10.9) of compressible-washer-type direct tension indicators, in nominal diameter sizes M16 through M36, capable of indicating the achievement of a specified minimum bolt tension in a structural bolt and are intended for installation under either a bolt head or a hardened washer. Steel materials used in the manufacture of direct tension indicators shall be designed, processed, heat treated, and protectively coated as specified. The direct tension indicators shall conform to required chemical composition, compression load, outside diameter, number of protrusions, thickness values, inside diameter, and protrusion tangential diameter values.

1.1 This specification covers the requirements for compressible-washer-type direct tension indicators capable of indicating the achievement of a specified minimum bolt tension in a structural bolt.

1.2 Two types of direct tension indicators in nominal diameter sizes M16 through M36 are covered:

1.2.1 Type 8.8—direct tension indicators for use with Specification A 325M bolts, and

1.2.2 Type 10.9—direct tension indicators for use with Specification A 490M bolts.

1.3 Direct tension indicators are intended for installation under either a bolt head or a hardened washer. (See Research Council on Structural Connections: Specification for Structural Joints Using ASTM A 325 or A 490 Bolts.)

1.4 The following precautionary statement pertains only to the test methods portions, Section 12, and Appendix X1 of this specification: This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.