This specification covers steel cleanliness requirements in inch/pound units for aircraft-quality, ferro-magnetic, hardenable, corrosion-resistant steels as determined by magnetic particle inspection methods. This specification contains sampling, specimen preparation, and inspection procedures and cleanliness rating criteria (See 8.2). The metric version, MAM2303, has been cancelled. The SI units have been included in this specification, but the inch-pound units are primary (See 8.5).