ASTM F2482/F2482M-21

Standard Specification for Load-Indicating Externally Threaded Fasteners

ABSTRACT
This specification covers externally threaded bolts, studs, and cap screws called fasteners, capable of indicating clamping forces up to yield strength during the tightening process or post installation residual tension, or both. Load-indicating fasteners utilize mechanical, electronic, or ultrasonic means to indicate fastener tension. These fasteners provide a means to verify the desired clamp load in critical applications upon installation and in service. This specification covers the following four different types of load-indicating fasteners: mechanical dial type (MT); electronic type (ET); strain gauge type (ST); and ultrasonic type (UT). Tension test shall be performed to conform to the chemical and mechanical requirements specified.
SCOPE
1.1 This specification covers externally threaded bolts, studs, and cap screws, herein called fasteners, capable of indicating clamping forces up to yield strength during the tightening process or post installation residual tension, or both. Load-indicating fasteners utilize a variety of sensor types to indicate fastener tension. This specification outlines the various types of load indication technologies available and defines their performance requirements.  
1.2 This specification covers fastener diameters 1/4 to 7 in. [M6 to M180] inclusive. Fasteners are manufactured from a variety of material types and grades. All fastener materials shall be defined by a governing engineering standard or specification for strength and performance values (see 6.1). Fasteners governed by this specification shall maintain traceability of material test records throughout the manufacturing process to verify conformance with the applicable fastener standards.  
1.3 These fasteners provide a means to verify the desired clamp load in critical applications upon installation and in service.  
1.4 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined.  
1.5 The following precautionary statement pertains only to the test method portion, Section 11, of the 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.6 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.

General Information

• Status: Published
• Publication Date: 30-Nov-2021
• ICS: 21.060.10 - Bolts, screws, studs
• Technical Committee: F16 - Fasteners
• Drafting Committee: F16.02 - Steel Bolts, Studs and Nuts

Relations

• Refers: ASTM F1470-24 - Standard Practice for Fastener Sampling for Specified Mechanical Properties and Performance Inspection
• Effective Date: 01-Jan-2024
• Refers: ASTM F1789-23 - Standard Terminology for F16 Mechanical Fasteners
• Effective Date: 01-Nov-2023
• Refers: ASTM F1470-18 - Standard Practice for Fastener Sampling for Specified Mechanical Properties and Performance Inspection
• Effective Date: 01-Feb-2018
• Refers: ASTM F1789-17 - Standard Terminology for F16 Mechanical Fasteners
• Effective Date: 01-Jun-2017
• Refers: ASTM F1789-16 - Standard Terminology for F16 Mechanical Fasteners
• Effective Date: 01-Aug-2016
• Refers: ASTM F1789-15a - Standard Terminology for F16 Mechanical Fasteners
• Effective Date: 01-Mar-2015
• Refers: ASTM F1789-15 - Standard Terminology for F16 Mechanical Fasteners
• Effective Date: 01-Feb-2015
• Refers: ASTM F1789-14a - Standard Terminology for F16 Mechanical Fasteners
• Effective Date: 01-Sep-2014
• Refers: ASTM E4-14 - Standard Practices for Force Verification of Testing Machines
• Effective Date: 01-Jun-2014
• Refers: ASTM F1789-14 - Standard Terminology for F16 Mechanical Fasteners
• Effective Date: 01-Feb-2014
• Refers: ASTM F1789-12a - Standard Terminology for F16 Mechanical Fasteners
• Effective Date: 01-Dec-2012
• Refers: ASTM F1470-12 - Standard Practice for Fastener Sampling for Specified Mechanical Properties and Performance Inspection
• Effective Date: 15-Nov-2012
• Refers: ASTM F1789-12 - Standard Terminology for F16 Mechanical Fasteners
• Effective Date: 01-Jun-2012
• Refers: ASTM F1789-11b - Standard Terminology for F16 Mechanical Fasteners
• Effective Date: 01-Nov-2011
• Refers: ASTM F1789-11a - Standard Terminology for F16 Mechanical Fasteners
• Effective Date: 01-Nov-2011

Overview

ASTM F2482/F2482M-21 is a comprehensive standard specification developed by ASTM International covering load-indicating externally threaded fasteners, including bolts, studs, and cap screws. These fasteners are engineered to accurately indicate clamping forces up to the yield strength during the tightening process or to verify residual tension after installation. The specification applies to fasteners ranging from 1/4 inch to 7 inches (M6 to M180) in diameter and encompasses products manufactured from various material grades, each defined by a recognized engineering standard.

Load-indicating fasteners specified by ASTM F2482/F2482M-21 use mechanical, electronic, or ultrasonic technologies to monitor fastener tension, providing a reliable method for verifying clamp load in critical applications both at installation and during service life. Adherence to this standard ensures traceability, accuracy, and consistency for safety-critical bolted connections.

Key Topics

• Types of Load-Indicating Fasteners: ASTM F2482/F2482M-21 classifies fasteners into several types based on their load-indication technology:

  • Mechanical Dial Type (MT): Incorporates a dial on the head to display tension.
  • Electronic Type (ET): Uses electronic devices at the head or end for digital tension readings.
  • Strain Gauge Type (ST): Incorporates bonded strain gauges configured in a Wheatstone Bridge to monitor tension.
  • Ultrasonic Type (UT): Uses pulse-echo ultrasonic measurement to determine tension.
  • Optical Type (OT): Employs visual or fiber optic indicators (where applicable).
  • Electronic Wireless Type (EW): Capable of wireless tension transmission.

• Performance and Calibration:

  • Fasteners must be calibrated for accuracy to within specified tolerances up to full-scale load.
  • Load tolerance options include ±5%, ±10%, and ±20% of full-scale load.
  • Field testing and calibration reports are critical to ensuring ongoing accuracy.

• Materials and Traceability:

  • All fastener materials must comply with governing standards for strength and performance.
  • Detailed traceability of material and calibration records is required throughout manufacturing.

• Certifications and Reporting:

  • Certificates of compliance and calibration accuracy reports are mandatory when specified by purchase order.

Applications

• Structural Engineering: Used in steel structures where precise bolt tension is critical for load transfer and safety.
• Bridges and Infrastructure: Essential for ensuring the proper clamp force in bridge connections and other infrastructure projects to prevent loosening or fatigue.
• Heavy Equipment and Machinery: Applied in equipment assemblies where preload verification is crucial for performance and reliability.
• Power Generation Facilities: Ensures safe bolted joints in high-stress turbine or generator installations.

These fasteners offer a significant advantage in safety-critical environments by providing direct tension verification during installation and subsequent inspection, reducing the risk of failed connections due to improper preload.

Related Standards

The following ASTM and international standards are frequently referenced alongside ASTM F2482/F2482M-21 for the selection and performance of load-indicating fasteners:

• ASTM A193/A193M: Alloy-Steel and Stainless Steel Bolting for High Temperature or High Pressure Service
• ASTM A354: Quenched and Tempered Alloy Steel Bolts and Studs
• ASTM A449: Hex Cap Screws, Bolts and Studs, Steel, Heat Treated
• ASTM E4: Force Calibration and Verification of Testing Machines
• ASTM E1685: Ultrasonic Pulse-Echo Technique for Bolt Measurement
• ASTM F1470: Sampling for Mechanical Fasteners
• ISO 898-1: Mechanical Properties of Carbon or Alloy Steel Fasteners
• ASME B18.2.1: Bolts and Screws - Inch Series

By adhering to ASTM F2482/F2482M-21, organizations can ensure the reliability and safety of bolted connections in demanding environments while meeting international best practices for structural fasteners.

Standards Content (Sample)

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: F2482/F2482M −21
Standard Specification for
Load-Indicating Externally Threaded Fasteners
ThisstandardisissuedunderthefixeddesignationF2482/F2482M;thenumberimmediatelyfollowingthedesignationindicatestheyear
of original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.
A superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope* ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom-
1.1 This specification covers externally threaded bolts,
mendations issued by the World Trade Organization Technical
studs, and cap screws, herein called fasteners, capable of
Barriers to Trade (TBT) Committee.
indicating clamping forces up to yield strength during the
tighteningprocessorpostinstallationresidualtension,orboth.
2. Referenced Documents
Load-indicating fasteners utilize a variety of sensor types to
2.1 ASTM Standards:
indicatefastenertension.Thisspecificationoutlinesthevarious
E4Practices for Force Calibration and Verification of Test-
typesofloadindicationtechnologiesavailableanddefinestheir
ing Machines
performance requirements.
E1685PracticeforMeasuringtheChangeinLengthofBolts
1.2 This specification covers fastener diameters ⁄4 to 7 in.
Using the Ultrasonic Pulse-Echo Technique
[M6 to M180] inclusive. Fasteners are manufactured from a
F1470Practice for Fastener Sampling for Specified Me-
variety of material types and grades. All fastener materials
chanical Properties and Performance Inspection
shall be defined by a governing engineering standard or
F1789Terminology for F16 Mechanical Fasteners
specification for strength and performance values (see 6.1).
2.2 ASME Standard:
Fasteners governed by this specification shall maintain trace-
B18.2.1Square, Hex, Heavy Hex, and Askew Head Bolts
ability of material test records throughout the manufacturing
and Hex, Heavy Hex, Hex Flange, Lobed Head, and Lag
process to verify conformance with the applicable fastener
Screws (Inch Series)
standards.
2.3 ISO Standard:
1.3 These fasteners provide a means to verify the desired
ISO 898-1Mechanical Properties of fasteners made of
clamp load in critical applications upon installation and in
carbon or alloy steel Part -1
service.
1.4 The values stated in either SI units or inch-pound units
3. Terminology
are to be regarded separately as standard. The values stated in
3.1 Terms used in this specification are defined in Termi-
eachsystemarenotnecessarilyexactequivalents;therefore,to
nology F1789, unless otherwise specified herein.
ensure conformance with the standard, each system shall be
3.2 Definitions:
used independently of the other, and values from the two
3.2.1 calibration of accuracy lot—lot shall consist of all
systems shall not be combined.
load-indicating fasteners processed essentially together
1.5 The following precautionary statement pertains only to
through all operations to the shipping container that are of the
the test method portion, Section 11, of the specification: This
same nominal size, the same nominal length, and
standard does not purport to address all of the safety concerns,
manufactured/calibrated from the same mill heat of steel. This
if any, associated with its use. It is the responsibility of the user
lotisusedforthepurposeofassigninganidentificationnumber
of this standard to establish appropriate safety, health, and
and from which calibrated samples shall be selected.
environmental practices and determine the applicability of
regulatory limitations prior to use.
1.6 This international standard was developed in accor-
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
dance with internationally recognized principles on standard-
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
1 3
This specification is under the jurisdiction of ASTM Committee F16 on Available from American Society of Mechanical Engineers (ASME), ASME
Fasteners and is the direct responsibility of Subcommittee F16.02 on Steel Bolts, International Headquarters, Two Park Ave., New York, NY 10016-5990, http://
Nuts, Rivets and Washers. www.asme.org.
Current edition approved Dec. 1, 2021. Published January 2022. Originally Available from International Organization for Standardization (ISO), ISO
approvedin2005.Lastpreviouseditionapprovedin2015asF2482–08(2015).DOI: Central Secretariat, Chemin de Blandonnet 8, CP 401, 1214 Vernier, Geneva,
10.1520/F2482_F2482M-21. Switzerland, https://www.iso.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
F2482/F2482M − 21
3.2.2 load-indicating fastener—externally threaded fastener do conform (see 6.1) to the stated material strengths (psi,
equipped with a load indicating device capable of measuring MPa), a reduced loadability designation shall be used to mark
fastener tension during the tightening process or residual
the product.
tension after tightening, or both.
6.1.1.1 For inch product, an asterisk, *, may be used to
designate the reduced loadability.
4. Classification
6.1.1.2 Formetricproduct,aleading“0”infrontoftheclass
4.1 This specification covers the following types of load-
marking is acceptable per ISO 898-1.
indicating fasteners:
6.1.1.3 The material test records for the modified product
4.1.1 Mechanical Dial Type (MT)—This type of fastener
shall reflect the magnitude of reduced loadability.
incorporatesadialontheheadoftheboltorendofthestudthat
6.1.1.4 Other marking methods that adequately convey the
continuously displays the tension in the fastener.
reduced loadability designation to the end user will be accept-
4.1.2 Electronic Type (ET)—This type of fastener employs
able.
an electronic measuring device attached to the head or end to
6.1.1.5 RefertoISO898-1foramorecompletedefinitionof
obtain readings indicating the tension in the fastener.
reduced loadability.
4.1.3 Strain Gauge Type (ST)—This type of fastener incor-
porates a bonded device wired in a wheatstone bridge configu- 6.2 Load-indicating fasteners are capable of displaying load
ration which, through changes in relative resistance, reports
up to their full-scale specifications. Common full-scale load
tension in the fastener. specifications are Design Load, Proof Load, and Yield Load.
4.1.4 Ultrasonic Type (UT)—This type of fastener incorpo- (1)Design Load is defined as a tensile load value set as a
rates an acoustic coupling device using pulse-echo technique
percentage of the fastener’s proof or yield strength.
capable of converting time-of-flight (TOF) measurements into (2)Proof Load is the tensile load value equal to the
existing fastener tension.
fastener’s proof strength.
4.1.5 Optical Type (OT)—This type of fastener incorporates
(3)Yield Load is the tensile load value equal to the
an optical indicator in the head of the bolt that can indicate fastener’s yield strength.
tension visually and/or by fiber optic sensor measurement.
6.2.1 Type MT load-indicating fasteners shall incorporate a
4.1.6 Electronic Wireless (EW)—This type of fastener em-
calibrated dial capable of displaying fastener tension readings
ploys an electronic measuring device attached to the head or
up to the yield strength of the fastener.
end that can indicate and transmit fastener tension wirelessly.
6.2.2 Type ET load-indicating fasteners shall incorporate a
measuring device capable of displaying load indications up to
5. Ordering Information
the yield strength on a digital readout.
5.1 Orders for load indicating fasteners shall include the
6.2.3 Type ST load-indicating fasteners shall incorporate
following:
permanently bonded electronic-resistance devices configured
5.1.1 Quantity;
in a Wheatstone Bridge configuration. The fastener shall then
5.1.2 Size, including nominal diameter, thread pitch and
be capable of being connected to an electronic unit to measure
length;
installedtensionbetween0 and100%oftheproofstrengthof
5.1.3 Head style of fastener component;
the fastener.
5.1.4 ASTM F2482/F2482Mdesignation,Type XX (Section
6.2.4 TypeUTload-indicatingfastenersshallincorporatean
4), full-scale load value (6.2), and load tolerance (8.2);
acoustic coupling device to the end of the fastener, using a
5.1.5 Material Grade or Engineering Specification, as appli-
pulse-echo technique capable of converting time-of-flight
cable for fastener component;
(TOF) measurements into existing fastener tension up to the
5.1.6 Coating or finish, if required;
yield strength of the fastener. (See Practice E1685.)
5.1.7 Testreport(s)orcertificate(s)(Section14),ifrequired;
6.2.5 TypeOTload-indicatingfastenersshallincorporatean
and
optical sensor capable of signaling fastener tension visually
5.1.8 Special requirements, if required.
and/orbecapableofconnectingtoafiberopticcouplingdevice
that measures the fastener load up to the yield strength of the
NOTE 1—A typical ordering information follows: 1000 pieces,
1in.–8in.×8in. Heavy Hex Structural BoltASTM F2482/F2482MType
fastener.
MT, Proof Load, LT1, Grade A325-1, ASTM F1941 Fe/Zn, 5C Coating.
6.2.6 TypeEWloadindicatingfastenersshallincorporatean
Calibration Accuracy Test Report required.
electronic measuring device capable of measuring, converting,
and wirelessly transmitting fastener tension up to the yield
6. Materials and Manufacture
strength to a receiving device.
6.1 All load-indicating fasteners shall be manufactured or
processed to ensure no degradation of the mechanical proper-
7. Chemical and Mechanical Properties
ties of the fastener component from which the load-indicating
fastener is derived (see Section 7). 7.1 The chemical and mechanical properties shall be dic-
6.1.1 Reduced Loadability—Where applicable, if due to tated by the associated ASTM or other governing engineering
specification to which the load-indicating features are being
geometric modification, the fasteners no longer conform to the
specified material standard’s stated tensile load (klbf, kN) but added. See 1.2 for additional information.
F2482/F2482M − 21
8. Performance Requirements loads shall be within the verified loading range of the testing
machine in accordance with Practices E4.
8.1 Calibration of Accuracy—The load-indicating fastener
11.2.3 The tension measuring device shall be calibrated in
shall be calibrated to the specified load tolerance accuracy up
25% increments, as a minimum, up to the maximum load
to the full-scale load of the fastener unless otherwise specified
capacity of t
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: F2482 − 08 (Reapproved 2015) F2482/F2482M − 21
Standard Specification for
Load-Indicating Externally Threaded Fasteners
This standard is issued under the fixed designation F2482;F2482/F2482M; 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*
1.1 This specification covers externally threaded bolts, studs, and cap screws as defined in screws, Table 1, herein called fasteners,
capable of indicating clamping forces up to yield strength during the tightening process or post installation residual tension, or
both. Load-indicating fasteners utilize mechanical, electronic, or ultrasonic meansa variety of sensor types to indicate fastener
tension. This specification outlines the various types of load indication technologies available and defines their performance
requirements.
1.2 This specification covers boltfastener diameters ⁄4 to 7 in. inclusive.[M6 to M180] inclusive. Fasteners are manufactured from
a variety of material types and grades. All fastener materials shall be defined by a governing engineering standard or specification
for strength and performance values (see 6.1). Fasteners governed by this specification shall maintain traceability of material test
records throughout the manufacturing process to verify conformance with the applicable fastener standards.
1.3 These fasteners provide a means to verify the desired clamp load in critical applications upon installation and in service.
1.4 The values stated in either SI units or inch-pound units are to be regarded as standard. No other units of measurement are
included in this standard.separately as standard. The values stated in each system are not necessarily exact equivalents; therefore,
to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems
shall not be combined.
1.5 The following precautionary statement pertains only to the test method portion, Section 11, of the 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 safety, health, and healthenvironmental practices and determine the applicability
of regulatory limitations prior to use.
1.6 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.
2. Referenced Documents
2.1 ASTM Standards:
A193/A193M Specification for Alloy-Steel and Stainless Steel Bolting for High Temperature or High Pressure Service and Other
Special Purpose Applications
This specification is under the jurisdiction of ASTM Committee F16 on Fasteners and is the direct responsibility of Subcommittee F16.02 on Steel Bolts, Nuts, Rivets
and Washers.
Current edition approved May 1, 2015Dec. 1, 2021. Published August 2015January 2022. Originally approved in 2005. Last previous edition approved in 20082015 as
F2482–08.F2482–08(2015). DOI: 10.1520/F2482-08R15.10.1520/F2482_F2482M-21.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
*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
F2482/F2482M − 21
A325 Specification for Structural Bolts, Steel, Heat Treated, 120/105 ksi Minimum Tensile Strength (Withdrawn 2016)
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
A490 Specification for Structural Bolts, Alloy Steel, Heat Treated, 150 ksi Minimum Tensile Strength (Withdrawn 2016)
E4 Practices for Force Calibration and Verification of Testing Machines
E1685 Practice for Measuring the Change in Length of Bolts Using the Ultrasonic Pulse-Echo Technique
F1470 Practice for Fastener Sampling for Specified Mechanical Properties and Performance Inspection
F1789 Terminology for F16 Mechanical Fasteners
2.2 ASME Standard:
B18.2.1 Square, Hex, Heavy Hex, and Askew Head Bolts and Hex, Heavy Hex, Hex Flange, Lobed Head, and Lag Screws (Inch
Series)
2.3 ISO Standard:
ISO 898-1 Mechanical Properties of fasteners made of carbon or alloy steel Part -1
3. Terminology
3.1 Terms used in this specification are defined in Terminology F1789, unless otherwise specified herein.
3.2 Definitions:
3.2.1 calibration of accuracy lot—lot shall consist of all load-indicating fasteners processed essentially together through all
operations to the shipping container that are of the same nominal size, the same nominal length, and manufactured/calibrated from
the same mill heat of steel. This lot is used for the purpose of assigning an identification number and from which calibrated samples
shall be selected.
3.2.2 load-indicating fastener—externally threaded fastener equipped with a load indicating device capable of measuring fastener
tension during the tightening process or residual tension after tightening, or both.
4. Classification
4.1 This specification covers the following four different types of load-indicating fasteners:
4.1.1 Mechanical Dial Type (MT)—This type of fastener incorporates a dial on the head of the bolt or end of the stud that
continuously displays the tension in the fastener.
4.1.2 Electronic Type (ET)—This type of fastener employs an electronic measuring device attached to the head or end to obtain
readings indicating the tension in the fastener.
4.1.3 Strain Gauge Type (ST)—This type of fastener incorporates a bonded device wired in a wheatstone bridge configuration
which, through changes in relative resistance, reports tension in the fastener.
4.1.4 Ultrasonic Type (UT)—This type of fastener incorporates an acoustic coupling device using pulse-echo technique capable
of converting time-of-flight (TOF) measurements into existing fastener tension.
4.1.5 Optical Type (OT)—This type of fastener incorporates an optical indicator in the head of the bolt that can indicate tension
visually and/or by fiber optic sensor measurement.
4.1.6 Electronic Wireless (EW)—This type of fastener employs an electronic measuring device attached to the head or end that can
indicate and transmit fastener tension wirelessly.
4.2 Various grades are listed in Table 1.
The last approved version of this historical standard is referenced on www.astm.org.Available from American Society of Mechanical Engineers (ASME), ASME
International Headquarters, Two Park Ave., New York, NY 10016-5990, http://www.asme.org.
Available from International Organization for Standardization (ISO), ISO Central Secretariat, Chemin de Blandonnet 8, CP 401, 1214 Vernier, Geneva, Switzerland,
https://www.iso.org.
F2482/F2482M − 21
5. Ordering Information
5.1 Orders for load indicating fasteners shall include the following:
5.1.1 Quantity;
5.1.2 Size, including nominal diameter, thread pitch and length;
5.1.3 Head style of fastener component;
5.1.4 ASTM F2482/F2482Mdesignation, Type XX (Section 4), full-scale load value (6.2), and load tolerance (8.2);
5.1.5 ASTM designation, grade, and type,Material Grade or Engineering Specification, as applicable for fastener component (see
component;4.1 and Table 1);
5.1.6 Coating or finish, if required;
5.1.7 Test reportreport(s) or certificate ofcertificate(s) (Section 14compliance,), if required; and
5.1.8 Special requirements, if required.
NOTE 1—A typical ordering information follows: 1000 pieces, 1-8 × 8 1 in.–8 in. × 8 in. Heavy Hex Structural Bolt ASTM XXXXF2482/F2482M Grade.
325-1, Mechanical Dial, Electrodeposited Zinc CoatingType MT, Proof Load, LT1, Grade A325-1, ASTM F1941 Coating FeZn, Thickness 5.
IncludeFe/Zn, 5C Coating. Calibration Accuracy Test Report required.
6. Materials and Manufacture
6.1 All load-indicating fasteners shall be manufactured or processed to ensure no degradation of the mechanical properties of the
fastener component from which the load-indicating fastener is derived (see Section 7).
6.1.1 Reduced Loadability—Where applicable, if due to geometric modification, the fasteners no longer conform to the specified
material standard’s stated tensile load (klbf, kN) but do conform (see 6.1) to the stated material strengths (psi, MPa), a reduced
loadability designation shall be used to mark the product.
6.1.1.1 For inch product, an asterisk, *, may be used to designate the reduced loadability.
6.1.1.2 For metric product, a leading “0” in front of the class marking is acceptable per ISO 898-1.
6.1.1.3 The material test records for the modified product shall reflect the magnitude of reduced loadability.
6.1.1.4 Other marking methods that adequately convey the reduced loadability designation to the end user will be acceptable.
6.1.1.5 Refer to ISO 898-1 for a more complete definition of reduced loadability.
6.2 All load-indicating fasteners shall be manufactured or processed to ensure no degradation of the mechanical properties of the
fastener component from which the load-indicating fastener is derived (see SectionLoad-indicating fasteners are capable of
displaying load up to their full-scale specifications. Common full-scale load specifications are Design Load, Proof Load, 7).and
Yield Load.
(1) Design Load is defined as a tensile load value set as a percentage of the fastener’s proof or yield strength.
(2) Proof Load is the tensile load value equal to the fastener’s proof strength.
(3) Yield Load is the tensile load value equal to the fastener’s yield strength.
6.2.1 Type MT load-indicating fasteners shall incorporate a calibrated dial capable of displaying fastener tension readings up to
the yield strength of the fastener.
6.2.2 Type ET load-indicating fasteners shall incorporate a measuring device capable of displaying load indications up to the yield
strength on a digital readout.
F2482/F2482M − 21
6.2.3 Type ST load-indicating fasteners shall incorporate permanently bonded electronic-resistance devices configured in a
Wheatstone Bridge configuration. The fastener shall then be capable of being connected to an electronic unit to measure installed
tension between 0 and 100 % of the proof-load proof strength of the fastener.
6.2.4 Type UT load-indicating fasteners shall incorporate an acoustic coupling device to the end of the fastener, using a pulse-echo
technique capable of converting time-of-flight (TOF) measurements into existing fastener tension (see up to the yield strength of
the fastener. (See Practice E1685).)
6.2.5 Type OT load-indicating fasteners shall incorporate an optical sensor capable of signaling fastener tension visually and/or
be capable of connecting to a fiber optic coupling device that measures the fastener load up to the yield strength of the fastener.
6.2.6 Type EW load indicating fasteners shall incorporate an electronic measuring device capable of measuring, converting, and
wirelessly transmitting fastener tension up to the yield strength to a receiving device.
7. Chemical and Mechanical Properties
7.1 The chemical and mechanical properties shall be dictated by the associated ASTM or other governing engineering specification
to which the load-indicating features are being added. See Table 11.2. for additional information.
8. Performance Requirements
8.1 Calibration of Accuracy—The load-indicating fastener shall be calibrated to 65 % the specified load tolerance accuracy up
to the prooffull-scale load of the fastener unless otherwise specified at the time of order.
8.2 Load Tolerance—The load-indicating fastener can be specified to conform with multiple load tolerances.
LT1: 6 5 % of full-scale load
LT2: 6 10 % of full-scale load
LT3: 6 20 % of full-scale load
8.2.1 All load-indicating fastener types may be specified to the load tolerance that meets or exceeds the needs of the application.
8.3 Field Tests—The purchaseruser shall have the option of specifying calibration accuracy test reports from the manufacturer or
performing field tests to verify calibration accuracy. When exercised, the lo
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