ASTM F959/F959M-17a(2023)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: F959/F959M − 17a (Reapproved 2023)
Standard Specification for
Compressible-Washer-Type Direct Tension Indicators for
Use with Structural Fasteners, Inch and Metric Series
This standard is issued under the fixed designation F959/F959M; the number immediately following the designation indicates the year
of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval.
A superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope* 1.6 The values stated in either SI units or inch-pound units
are to be regarded separately as standard. The values stated in
1.1 This specification covers the requirements for
each system are not necessarily exact equivalents; therefore, to
compressible-washer-type direct tension indicators, (DTIs)
ensure conformance with the standard, each system shall be
capable of indicating the achievement of a specified minimum
used independently of the other, and values from the two
tension in a structural bolting assembly.
systems shall not be combined.
1.2 Eight types of DTIs in nominal diameter sizes ⁄2
1.7 The following precautionary statement pertains only to
through 1 ⁄2 in. as well as M16 through M36 are covered:
the test method portions, Section 10 and Appendix X1 of this
1.2.1 Type 325-1—DTIs for use with Specification F3125
specification: This standard does not purport to address all of
Grade A325 Type 1 bolts or Grade F1852 assemblies.
the safety concerns, if any, associated with its use. It is the
1.2.2 Type 325–3—DTIs for use with Specification F3125
responsibility of the user of this standard to establish appro-
Grade A325 Type 3 bolts or Grade F1852 Type 3 assemblies.
priate safety, health, and environmental practices and deter-
1.2.3 Type 490–1—DTIs for use with Specification F3125
mine the applicability of regulatory limitations prior to use.
Grade A490 Type 1 bolts or Grade F2280 assemblies.
1.8 This international standard was developed in accor-
1.2.4 Type 490–3—DTIs for use with Specification F3125
dance with internationally recognized principles on standard-
Grade A490 Type 3 bolts Grade F2280 Type 3 assemblies.
ization established in the Decision on Principles for the
1.2.5 Type 8.8-1—DTIs for use with Specification F3125 Development of International Standards, Guides and Recom-
Grade A325M Type 1 bolts.
mendations issued by the World Trade Organization Technical
1.2.6 Type 8.8-3—DTIs for use with Specification F3125 Barriers to Trade (TBT) Committee.
Grade A325M Type 3 bolts.
2. Referenced Documents
1.2.7 Type 10.9-1—DTIs for use with Specification F3125
2.1 ASTM Standards:
Grade A490M Type 1 bolts.
A325 Specification for Structural Bolts, Steel, Heat Treated,
1.2.8 Type 10.9-3—DTIs for use with Specification F3125
120/105 ksi Minimum Tensile Strength (Withdrawn
Grade A490M Type 3 bolts.
2016)
1.3 DTIs are intended for installation with the protrusions
A325M Specification for Structural Bolts, Steel, Heat
against a hardened surface such as a bolt head, a hardened nut,
Treated 830 MPa Minimum Tensile Strength (Metric)
or a hardened washer. (See Research Council on Structural
(Withdrawn 2016)
Connections: Specification for Structural Joints Using High-
A490 Specification for Structural Bolts, Alloy Steel, Heat
–Strength Bolts.)
Treated, 150 ksi Minimum Tensile Strength (Withdrawn
2016)
1.4 This specification provides for furnishing Type 3 DTIs
A490M Specification for High-Strength Steel Bolts, Classes
to a Chemical Composition Requirement or a Corrosion
10.9 and 10.9.3, for Structural Steel Joints (Metric)
Resistance Index (CRI) at the manufacturer’s discretion.
(Withdrawn 2016)
1.5 Terms used in this specification are defined in Termi-
A1059 Specification for Zinc Alloy Thermo-Diffusion Coat-
nology F1789 unless otherwise specified.
ings (TDC) on Steel Fasteners, Hardware, and Other
Products
1 2
This specification is under the jurisdiction of ASTM Committee F16 on For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Fasteners and is the direct responsibility of Subcommittee F16.06 on Steel Washers contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
and Rivets. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved Nov. 1, 2023. Published November 2023. Originally the ASTM website.
approved in 1985. Last previous edition approved in 2017 as F959 – 17a. DOI: The last approved version of this historical standard is referenced on
10.1520/F0959-17AR23. www.astm.org.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F959/F959M − 17a (2023)
B695 Specification for Coatings of Zinc Mechanically De- 4.2.1 DTIs shall have a configuration produced by
posited on Iron and Steel extrusion, punching, pressing, or similar forming, to permit a
F436/F436M Specification for Hardened Steel Washers Inch measurable decrease in thickness when placed in compression.
and Metric Dimensions 4.2.2 The design shall be such that the degree of plastic
F606/F606M Test Methods for Determining the Mechanical
deformation shall indicate the tension in a tightened structural
Properties of Externally and Internally Threaded bolt. Supplementary indications of tension are permissible.
Fasteners, Washers, Direct Tension Indicators, and Rivets
4.3 Heat Treatment:
F1470 Practice for Fastener Sampling for Specified Me-
4.3.1 The heat treatment of DTIs is optional at the manu-
chanical Properties and Performance Inspection
facturer’s discretion, provided the DTIs meet all of the me-
F1789 Terminology for F16 Mechanical Fasteners
chanical and performance requirements.
F1852 Specification for “Twist Off” Type Tension Control
4.3.2 If heat treatment is performed, the process shall be
Structural Bolt/Nut/Washer Assemblies, Steel, Heat
through-hardening by heating to a temperature above the upper
Treated, 120/105 ksi Minimum Tensile Strength (With-
transformation temperature, quenching in a liquid medium, and
drawn 2016)
tempering by reheating to not less than 800 °F ⁄427 °C.
F2280 Specification for “Twist Off” Type Tension Control
4.4 Protective Coatings:
Structural Bolt/Nut/Washer Assemblies, Steel, Heat
4.4.1 Unless otherwise specified, the DTIs shall be fur-
Treated, 150 ksi Minimum Tensile Strength (Withdrawn
2016) nished “plain” with the “as fabricated” surface finish without
protective coatings.
F3125 Specification for High Strength Structural Bolts and
Assemblies, Steel and Alloy Steel, Heat Treated, Inch 4.4.2 When “zinc coated” or “galvanized” is specified, the
Dimensions 120 ksi and 150 ksi Minimum Tensile DTIs shall be zinc coated by the mechanical deposition process
Strength, and Metric Dimensions 830 MPa and 1040 MPa in accordance with the requirements of Class 55 of Specifica-
Minimum Tensile Strength tion B695, or the DTIs shall be zinc coated by the thermal
G101 Guide for Estimating the Atmospheric Corrosion Re- diffusion process in accordance with the requirements of Class
sistance of Low-Alloy Steels 25 of Specification A1059.
4.4.3 Other coatings are to be used only when approved by
2.2 Research Council on Structural Connections:
the DTI manufacturer.
Specification for Structural Joints Using High–Strength
Bolts
5. Chemical Composition
2.3 ASME Standard:
ASME B18.2.6 Fasteners for Use in Structural Applications
5.1 DTIs shall conform to the full Heat Analysis specified in
ASME B18.2.6M Fasteners for Use in Structural Applica-
Table 1 or the requirements of 5.2.
tions
5.1.1 For all types furnished to the chemical compositions
in Table 1, Product Analysis may be made by the purchaser
3. Ordering Information
from finished DTIs representing each lot. The chemical com-
3.1 Orders for DTIs under this specification shall include
position shall conform to the requirements given in Table 1,
the following:
Product Analysis.
3.1.1 Quantity (number of pieces);
5.2 Type 3 products having Copper, Phosphorus, and Sulfur
3.1.2 Name of product (DTI);
conforming to Table 1 and a Corrosion Resistance Index of 6
3.1.3 Size, that is, nominal diameter;
or higher calculated on the basis of the Heat Analysis as
3.1.4 ASTM designation and year of issue (if not specified,
described in Guide G101 shall be considered acceptable. See
current issue shall be used);
Note 1.
3.1.5 Type required, 325-1, 325-3, 490-1, 490-3, 8.8-1,
8.8-3, 10.9-1, 10.9-3 (see 1.2); NOTE 1—The user is cautioned that the Guide G101 predictive equation
for calculation of an atmospheric corrosion index has been verified only
3.1.6 Coating type, if required (4.4);
for the composition limits stated in that guide.
3.1.7 Source inspection, if required (Section 11);
5.2.1 Product Analyses are not applicable to Type 3 indica-
3.1.8 Test reports, if required (Section 13); and
3.1.9 Any special requirements. tors furnished to a CRI of 6 or higher. Acceptance shall be
based on the CRI of 6 or higher calculated from the Heat
4. Materials and Manufacture
Analysis. Other specified Type 3 Steels with Copper,
Phosphorus, and Sulfur conforming to the specified limits and
4.1 Steel used in the manufacture of DTIs shall be produced
a Corrosion Resistance of 6 or higher, are acceptable in lieu of
by the basic-oxygen or electric-furnace process.
compliance with the full specified Chemical Compositions.
4.2 Design:
6. Performance Requirements
Available from Research Council on Structural Connections at www.boltcoun-
6.1 Compression Loads—When the gap of inch series DTIs
cil.org.
are compressed to 0.015 in. or metric series DTIs to 0.4 mm,
Available from American Society of Mechanical Engineers (ASME), ASME
the compression load shall conform to the requirements speci-
International Headquarters, Three Park Ave., New York, NY 10016-5990, http://
www.asme.org. fied in Table 2.
F959/F959M − 17a (2023)
TABLE 1 Chemical Composition Requirements
Composition, %
Element
Heat Product
Analysis Analysis
A A
Type 1 Series Type 3 Series Type 1 Series Type 3 Series
Carbon 0.30–0.55 . 0.27–0.58 .
Manganese 0.50–0.90 . 0.47–0.93 .
Phosphorus
...