This specification covers steel cleanliness requirements for aircraft-quality ferro-magnetic steels@ other than hardenable corrosion-resistant steels@ by magnetic particle inspection methods. Applicable primarily to blooms@ billets@ tube rounds@ stock for forging or flash welded rings@ slabs@ pars@ 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.