fit flush against the punch retainer 10 the precision threaded plug 28 is designed to bottom out in its mating pocket in the stripper body 20 which automatically sets the die spring 26 pre load and is fail safe so the spring cannot be overloaded unlike some stripper units currently available the new stripper unit 18 universally fits all standard ball lock punch retainers and most importantly requires no retainer alterations the movable or traveling stripper 22 is preferably of a hardened tool steel construction with a lubricating coating to promote smooth stripping movement the stripper 22 is guided not only by the u201c d u201d body shape but also by the stripper 39 s head diameter or hole size and shape 24 this provides a much improved condition that will ensure the stripper 22 cannot twist or cock and jam during production and will better facilitate side load to the stripper when stripping non flat surfaces the round portion of the stripper 22 and all the round features of the stripper unit 18 are co located along the centerline of the punch and pierced hole which simplifies design and manufacture of the stripper unit the unique u201c d u201d shape 40 of the stripper 22 provides a failsafe assembly allowing the stripper 22 to be assembled in the stripper body 20 only in the correct position the pre loading of the die spring 26 and stripper 22 provides instant stripping force upon contact with the work piece the instant stripping force on.