This dimpler produces a circular bullet hit depression in car bodies without the distortion associated with an air hammer. The dimpler features a roller thrust bearing for ease of operation, and a 1/4'-20 threaded hole in the female die to enable reaching into body panels.
The Dimpler is easy and quick to use. Simply drill a 5/16' (8mm) hole where you want the bullet hit. Set the female die inside the car body with the concave side lined up with the drilled hole. Assemble the male die with the bolt threads poking out the convex end and the needle bearing sandwiched between the bearing washers. Insert the threaded end through the 5/16' hole and screw it into the concave die, then tighten with a 1/2' (or 13mm) wrench until tight. That's it. Just unscrew the dies and remove and there's your dimple ready to install a squib. About a minute per dimple, including drilling the hole.