Active Standard ASTM A939 / A939M | Developed by Subcommittee: A01.06
Book of Standards Volume: 01.05
Historical (view previous versions of standard)
Significance and Use
3.1 This practice shall be used when ultrasonic inspection from the bore surface is required by the order or specification for inspection purposes in which the acceptance of the forging is based on limitations of the number, amplitude, or location of discontinuities or a combination thereof, which leads to ultrasonic indications.
1.4 This practice is expressed in inch-pound and SI units; however, the inch-pound units shall apply unless the purchase order or contract specifies the applicable “M” specification designation (SI units). The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.
ICS Number Code 77.140.85 (Iron and steel forgings)