ASTM F959

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 in., 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, and dimensional values.

This abstract is a brief summary of the referenced standard. It is informational only and not an official part of the standard; the full text of the standard itself must be referred to for its use and application. ASTM does not give any warranty express or implied or make any representation that the contents of this abstract are accurate, complete or up to date.

1. Scope

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 direct tension indicators in nominal diameter sizes ½ through 1 ½ in. are covered:

1.2.1 Type 325—direct tension indicators for use with Specification A 325 or F 1852 Type I bolts, nuts, and washers.

1.2.2 Type 325–3—direct tension indicators for use with Specification A 325 Type 3 bolts, nuts, and washers.

1.2.3 Type 490—direct tension indicators for use with Specification A 490 or F 2280 bolts, nuts, and washers.

1.2.4 Type 490–3—direct tension indicators for use with Specification A 490 Type 3 bolts, nuts, and washers.

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 method 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.

2. Referenced Documents

A325 Specification for Structural Bolts, Steel, Heat Treated, 120/105 ksi Minimum Tensile Strength
A490 Specification for Structural Bolts, Alloy Steel, Heat Treated, 150 ksi Minimum Tensile Strength
B695 Specification for Coatings of Zinc Mechanically Deposited on Iron and Steel
D3951 Practice for Commercial Packaging
F1470 Guide for Fastener Sampling for Specified Mechanical Properties and Performance Inspection
F1852 Specification for "Twist Off" Type Tension Control Structural Bolt/Nut/Washer Assemblies, Steel, Heat Treated, 120/105 ksi Minimum Tensile Strength
F2280 Specification for "Twist Off" Type Tension Control Structural Bolt/Nut/Washer Assemblies, Steel, Heat Treated, 150 ksi Minimum Tensile Strength
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
ASMEB18.2.6 Fasteners for Use in Structural Applications
Specification for Structural Joints Using ASTM A325 or A490 Bolts

Index Terms

compressible-washer-type; direct tension indicators; DTI; indicators; Compressible washer-type indicators; Direct tension indicators (DTI); Fasteners (metal) specifications; Indicators; Structural building materials/applications specifications; Structural fasteners; Tensile properties/testing metallic materials; ICS Number Code 21.060.01

Citing ASTM Standards

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