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. The metric version, MAM 2303, has been cancelled. The SI units have been included in this specification, but the inch-pound units are primary. This procedure has been used typically for the cleanliness evaluation of blooms, billets, tube rounds, stock for forging or flash welded rings, slabs, bars, sheet, strip, plate, tubing, and extrusions used in fabricating parts subject to magnetic particle inspection, but may be used for qualification of a heat, melt, or lot of steel.