BA 6 Helical Thread Insert Tap Second lead

Specification 6 BA Use to produce threads for helical coil wire screw thread inserts only S.T.I. taps are oversized so the thread produced accepts a helical coil wire screw thread insert of the same nominal size and pitch Taps are marked with the nominal size and pitch of the bolt to be used Taps are marked with ?S.T.I." Part Number ES-12539