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ASTM International · STANDARD

ASTM F959

Compressible-Washer-Type Direct Tension Indicators

§ 01

Overview

What this standard covers

Direct tension indicating washers used to verify bolt preload by measuring gap closure.

Direct tension indicating washers used to verify bolt preload by measuring gap closure.

Who uses it

Connection designers, fabricators and site teams selecting and tightening structural assemblies.

§ 02

Details

Reference data

Standard number
ASTM F959
Title
Compressible-Washer-Type Direct Tension Indicators
Organisation
ASTM International
Country
United States
Region
United States
Subject
Bolting
Subcategory
Preload verification
Type
STANDARD
Application
Contractual
Availability
Paid
Status
CURRENT
Roles
bolting standard
Last verified
2026-09-06

Official source: astm.org

§ 03

Related

Standards used alongside this one

  • RCSC Specification

    Specification for Structural Joints Using High-Strength Bolts

    The US bolting specification covering snug tight, pretensioned and slip critical joints, pre-installation verification and the four accepted tightening methods.

    United StatesBoltingCURRENTFree

  • ASTM F3125/F3125M

    High Strength Structural Bolts and Assemblies

    The consolidated specification covering grades A325, A490, F1852 and F2280 structural bolts and twist-off assemblies.

    United StatesBoltingCURRENTPaid

  • BS EN 14399-1

    High-strength structural bolting assemblies for preloading — General requirements

    The framework for preloaded assemblies: bolt, nut and washer are qualified together as a K-class assembly, not mixed between suppliers.

    United KingdomBoltingCURRENTPaid

  • BS EN 14399-10

    Preloaded bolting assemblies — System HRC bolt and nut assemblies with calibrated preload

    Tension control bolts whose spline shears off at the calibrated preload, giving a visible indication of correct tightening.

    United KingdomBoltingCURRENTPaid

  • BS EN 14399-3

    Preloaded bolting assemblies — System HR hexagon bolt and nut assemblies

    System HR assemblies in property classes 8.8 and 10.9, the common UK preloaded system.

    United KingdomBoltingCURRENTPaid

  • BS EN 14399-4

    Preloaded bolting assemblies — System HV hexagon bolt and nut assemblies

    System HV assemblies, which have shorter thread engagement and different ductility behaviour to HR.

    United KingdomBoltingCURRENTPaid

Sourcing, review and use

Status

Editorial reference information compiled and maintained by the StructuralSteel.ai team. It is not a design certificate and is not issued under an engineer's seal.

Last reviewed

Calculations

Any figures produced on this page are indicative estimates for early sizing and comparison only — they are not engineered design outputs.

References

Final member selection, loading, connection design, fire design, fabrication and compliance must be verified for your specific project by a suitably qualified structural engineer. Standards are revised; check the edition in force where the work is built.

Verification

StructuralSteel.ai provides technical reference information and links to authoritative sources. Project specifications, applicable legislation, current standards editions and requirements of the responsible engineer or authority should always be verified before fabrication or supply.