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 Four types of dir This specification covers the requirements for four types (Types 325, 325-3, 490, and 490-3) of compressible-washer-type direct tension indicators, in nominal diameter sizes ½ through 1 ½