Abstract: A draw punch of the type used for cutting holes in various materials such as sheet metal has a cylindrical body with a central bore through it and a cutting edge at the outside diameter of the body. A working face is defined at one end of the body between the cutting edge and the bore. The working face includes two diametral axial faces which extend from a root to a peak. The working face further includes two valleys located between the peak of one axial face and the root of the other axial face. Primary helical surfaces extend from a peak to a valley while secondary helical surfaces extend from the valley to the root. The helical surfaces are everywhere relieved in a radial direction from a plane normal to the axis of the body and intersecting any point on the cutting edge.

Abstract: This is concerned with a punch sometimes referred to as a draw punch which is constructed and arranged for enlarging holes in a large variety of materials, such as sheet metal, for example in junction boxes and the like where large tools cannot be used. More specifically this is concerned with a punch of the above type which is constructed and arranged to cut the metal or slug into two pieces so that they may be removed from the die without the assistance of a prying tool.