Notes
1. National Twist Drill & Tool Co. Detroit (Tagged Easter Etching & Mfg. Co., Springfield,; 2. Union Twist Dril Co., Athol Tool Bit Gge.; 3.Mechanix-Mate No. 1 & No. 2, Utility Products Corp. Spfld, Mass. Copyright 1960. 4. National Twist Drill & Tool Co., Detroit 1937