Yankee Hill Machine Forearm Wrench. Incorporated into the design is a tool for tightening the barrel nut and a spanner wrench for tightening the jam nut. Made from quality hardened steel and black oxide plated. Specifications for Yankee Hill Machine Forearm Wrench YHM-9621: Mfg Item Num: YHM-9621 Type: ACCESSORIES - GUN ACCESSORIES - GUNSMITHING TOOLS made in specialized factories: made in specialized factories Tactica: Tactical Master Model Header: Forearm Wrench The Yankee Hill Machine Forearm Wrench YHM-9621 is a quality addition to the Yankee Hill Machine lineup. For more great deals on Armorer's Wrenches by Yankee Hill Machine please browse our Yankee Hill Machine Gunsmithing Equipment page.