About this item This 1/8″ dimple die is designed to form a 100° countersink when working with thin aluminum or other soft metals when installing flush head rivets or other fasteners with a 100° head. A Dimple die set for sheet metal is typically used when flush fasteners are desired but the material is two thin to drill a countersink hole. Example 0.025″ aluminum. A dimple die requires a hand or pneumatic rivet squeezer to form the dimple in the sheet metal. These dies fit most such squeezers and feature a 0.187″ diameter shank. Spring back dimple dies are available in 4 separate sizes and as a 4 piece kit. If buying only one size make sure it fits the diameter of your fastener and that your fastener has a 100° head. THIS LISTING IS FOR THE DIMPLE DIE ONLY! RIVET SQUEEZERS ARE SOLD SEPERATELY!