HANSON RIVET DIMPLE DIES ARE DESIGNED TO FORM A 100° COUNTERSINK IN PRE-PUNCHED HOLES IN AN ALUMINUM SHEET. FOR 3/16" DIAMETER MS20426 AND MS20427 SERIES AND OTHER 100° COUNTERSUNK HEAD RIVETS. THESE DIES HAVE A POLISHED WORKING SURFACE. THE MALE IS 1/4" LONG AND THE FEMALE IS 3/8" LONG, BOTH WITH A .187" DIAMETER SHANK. (1 SET OF 2 DIES)