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ASTM F959/959M Direct Tension Washers Specification

Inch(Imperial) & Metric Series Direct Tension Indicators Compressible Washer for Use with Structural Fasteners

ASTM F959/959M Dti Washer, Compressible Type Washer

ASTM F959 / F959M specification covers the requirements for Inch(Imperial) & Metric Series Direct Tension Indicators Compressible Washer for Use with Structural Fasteners capable of indicating the achievement of a specified minimum tension in a structural bolting assembly. Eight types of DTIs in nominal diameter sizes 1/2 through 1 1/2 in. as well as M16 through M36 are covered. DTIs are intended for installation with the protrusions against a hardened surface such as a bolt head, a hardened nut, or a hardened washer. (See Research Council on Structural Connections: Specification for Structural Joints Using High-Strength Bolts.). Steel used in the manufacture of DTIs shall be produced by the basic-oxygen or electric-furnace process.

Related Specifications of ASTM F959/959M Bolting

A325 A490 F436 F3125

ASTM F959/959M Chemical Composition

Element Heat Analysis Product Analysis
Type 1 Series Type 3 SeriesA Type 1 Series Type 3 SeriesA
C 0.30-0.55 ... 0.27-0.58 ...
Mn 0.50-0.90 ... 0.47-0.93 ...
P, Max 0.04 0.040 0.048 0.045
S, Max 0.05 0.050 0.053 0.055
Si ... 0.15-0.35 ... 0.13-0.37
Cr ... 0.45-0.65 ... 0.42-0.68
Ni ... 0.25-0.45 ... 0.22-0.48
Cu ... 0.25-0.45 ... 0.22-0.48
  • (A) Type 3 DTIs are also permitted to be manufactured from any of the Type 3 steels in the chemical composition sections of Specification F3125. Unless otherwise specified, the manufacturer may use Type 3 steel to produce Type 1 product.

ASTM F959/959M Mechanical Requirements

ASTM F959 Acceptable Range of Compression Loads (in.)

DTI Size (Nominal Diameter, in.) Compression Load Range in Thousands of Pounds, (kips)
Types 325 and 325-3 Types 490 and 490-3
1/2 12-14 15-18
5/8 19-23 24-29
3/4 28-34 35-42
7/8 39-47 49-59
1 51-61 64-77
11/8 64-77 80-96
11/4 81-98 102-122
13/8 97-117 121-145
11/2 118-143 148-178

ASTM 959M Acceptable Range of Compression Loads (mm)

DTI Size (Nominal Diameter, mm) Compression Load Range for Metric Series in Kilonewtons, (kN)
Types 8.8-1 and 8.8-3 Types 10.9-1 and 10.9-3
M16 91-109 114-131
M20 142-170 179-206
M22 176-211 221-254
M24 205-246 257-296
M27 267-320 334-384
M30 326-391 408-469
M36 475-570 595-684

ASTM F959/959M Bolting Surface Treatment Specifications

ASTM F959/959M Bolting Components Marking

Product Shall be Marked with our manufacturing trade mark "TorqBolt" or "TB" along with the designated Grade.
Grade and manufacturer’s identification symbols shall be applied to one end of studs and to the heads of bolts and screws of all sizes. (If the available area is inadequate, the grade symbol may be marked on one end and the manufacturer’s identification symbol marked on the other end.) For bolts and screws smaller than 1⁄4 in. [6 mm] in diameter and studs smaller than 3⁄8 in. [10 mm] in diameter and for 1⁄4 in. [6 mm] in diameter studs requiring more than a total of three symbols, the marking shall be a matter of agreement between the purchaser and the manufacturer.

ASME Dimensional Standards

B18.2.6 Fasteners for Use in Structural Applications
B18.2.6M Fasteners for Use in Structural Applications

ASTM F959/959M Bolting Certifications

  • EN 10204 3.1
  • EN 10204 3.2
  • PED 2014/68/EC
  • MERKBLATT AD 2000 W2/W7/W10
  • API 20 E BSL 1/ BSL 2
  • NACE MR 0175
  • NACE MR 0103

ASTM F959/959M Testing Standards

A751 Test Methods, Practices, and Terminology for Chemical Analysis of Steel Products
F606/F606M Test Methods for Determining the Mechanical Properties of Externally and Internally Threaded Fasteners, Washers, Direct Tension Indicators, and Rivets