Blair 3/8" Double End Spotweld & Access Cutter, 3 Pack (BLR13214) Category: Hole Saws Spotweld cutters removes welded body fast and easy Hollow design cuts around weld, thus hardness does not affect tool sharpness An adjustable depth rod sets the tool so only the outer panel is cut through When one end becomes dull, simply reassemble with the new teeth exposed For use in any 1/4", 3/8", or 1/2" chuck hand held drill