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.

1.1 This specification covers externally threaded bolts, studs, and cap screws as defined in 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 means to indicate fastener tension.

1.2 This specification covers bolt diameters ¼ to 7 in. inclusive.

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 inch-pound units are to be regarded as standard. No other units of measurement are included in this standard.

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 and health practices and determine the applicability of regulatory limitations prior to use.