1. Scope

1.1 This specification covers the requirements for carbon and alloy steel compressible-washer-type direct tension indicators capable of indicating a specified bolt tension in cap screws, bolts, anchors, and studs.

1.2 Direct tension indicators in nominal diameter sizes 1/4 through 21/2 in. are covered.

1.3 There are two Types of DTIs covered by this specification, Type 1 and Type 2.

1.3.1 Type 1 DTIs are suitable for comparatively large bearing surfaces. Type 1 DTIs are available in Grades 55 and 105, which differ in the amount of tension they indicate at a prescribed gap (see ).

1.3.2 Type 2 DTIs are suitable for comparatively smaller bearing surfaces. Type 2 DTIs are available in Grades 5 and 8, which differ in the amount of tension they indicate at a prescribed gap (see ).

1.4 Direct tension indicators are intended for installation under a bolt or cap screw head, a hex nut, or against a hardened washer or other flat hardened surface.

The following precautionary statement pertains only to the test method portions, Section and Appendix XI 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.

2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.

ASTM Standards

A193/A193M Specification for Alloy-Steel and Stainless Steel Bolting for High Temperature or High Pressure Service and Other Special Purpose Applications

A194/A194M Specification for Carbon and Alloy Steel Nuts for Bolts for High Pressure or High Temperature Service, or Both

A307 Specification for Carbon Steel Bolts and Studs, 60 000 PSI Tensile Strength

A325 Specification for Structural Bolts, Steel, Heat Treated, 120/105 ksi Minimum Tensile Strength

A354 Specification for Quenched and Tempered Alloy Steel Bolts, Studs, and Other Externally Threaded Fasteners

A449 Specification for Hex Cap Screws, Bolts and Studs, Steel, Heat Treated, 120/105/90 ksi Minimum Tensile Strength, General Use

A563 Specification for Carbon and Alloy Steel Nuts

B633 Specification for Electrodeposited Coatings of Zinc on Iron and Steel

B695 Specification for Coatings of Zinc Mechanically Deposited on Iron and Steel

F436 Specification for Hardened Steel Washers

F606 Test Methods for Determining the Mechanical Properties of Externally and Internally Threaded Fasteners, Washers, Direct Tension Indicators, and Rivets

F1470 Practice for Fastener Sampling for Specified Mechanical Properties and Performance Inspection

F1554 Specification for Anchor Bolts, Steel, 36, 55, and 105-ksi Yield Strength

F1941 Specification for Electrodeposited Coatings on Threaded Fasteners (Unified Inch Screw Threads (UN/UNR))

ASME Standards

SAE Standard

Keywords

compressible-washer-type; direct tension indicators; DTI; load indicators; load indicating washers; tension indicators;

ICS Code

ICS Number Code 21.060.01 (Fasteners in general)

DOI: 10.1520/F2437-06

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