7/16X2 9/16 Magnetic Hex Driver Power Nutsetter Insert Bit (Pack Qty 10) BC-38-639

50BV30 steel (similar to SAE 6150) Rockwell C 42 - 48You may also like 2 7/8X1/4 Magnetic No C Ring Hex Insert Bit Holder (Pack Qty 10) BC-39-972.