Full Description

1.1This is an acceptance specification for the magnetic particle inspection of forged steel crankshafts having main bearing journals or crankpins 4 in. [200 mm] or larger in diameter.

1.2There are three classes, with acceptance standards of increasing severity:

1.2.1Class 1.

1.2.2Class 2 (originally the sole acceptance standard of this specification).

1.2.3Class 3 (formerly covered in Supplementary Requirement S1 of Specification A456-64 (1970)).

1.3This specification is not intended to cover continuous grain flow crankshafts (see Specification A983/A983M); however, Specification A986/A986M may be used for this purpose.

Note 1:Specification A668/A668M is a product specification which may be used for slab-forged crankshaft forgings that are usually twisted in order to set the crankpin angles, or for barrel forged crankshafts where the crankpins are machined in the appropriate configuration from a cylindrical forging.

1.4The 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.

1.5Unless the order specifies the applicable M specification designation, the material shall be furnished to the inch units.

1.6This 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.