Description

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

This specification provides for furnishing Type 3 DTIs to a Chemical Composition Requirement or a Corrosion Resistance Index (CRI) at the manufacturer’s discretion.  

Scope

Eight types of DTIs in nominal diameter sizes1⁄ 2 through 11⁄ 2 in. as well as M16 through M36 are covered: 

• Type 325-1—DTIs for use with Specification A325 Type 1 bolts or F or F1852 assemblies.  
• Type 325–3—DTIs for use with Specification A325 Type 3 bolts or F1852 Type 3 assemblies. 
• Type 490–1—DTIs for use with Specification A490 Type 1 bolts or F2280 assemblies.  
• Type 490–3—DTIs for use with Specification A490 Type 3 F2280 Type 3 assemblies.  
• Type 8.8-1—DTIs for use with Specification A325M Type 1 bolts.  
• Type 8.8-3—DTIs for use with Specification A325M Type 3 bolts.  
• Type 10.9-1—DTIs for use with Specification A490M Type 1 bolts.  
• Type 10.9-3—DTIs for use with Specification A490M Type 3 bolts.  

DTIs are intended for installation under either a bolt head or a hardened washer. (See Research Council on Structural Connections: Specification for Structural Joints Using High–Strength Bolts.)  

Terms used in this specification are defined in Terminology F1789 unless otherwise specified.  

The following precautionary statement pertains only to the test method portions, Section 10 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.