Clawson, Chris2020-04-132020-04-13https://dspace.montaguearchive.org/handle/MHS-01376/9322/25/48 GTD at Symmons Engr. Plant Boston Mass.; – Editor's Note: A tapered tap is threading a lathe mounted metal component.Greenfield Tap & Die Co.GTDGTD-Tools and Machinery – folder 1