North Bros. Yankee No. 1993 Machine Vise Swivel Base

This is a very clean hard to find, quality U.S.A. made machine vise quick change, rotating base, marked "YANKEE NO. 1993 NORTH BROS. MFG. CO. PHILA PA. U.S.A." on brass label on the side of the base. This base is designed to hold the No. 993 Yankee vise made by the same company (the largest size of it's type). There are a few different bases the hold the vise in the same way, and that is with a three surface angle lock (the matching machined surfaces on the vise), and one set screw to lock it down. This is perhaps one of the first interchangeable work holding machine tooling systems ever patented. Basically, the user could take the vice out of the machine, leaving a similar clamp in place on the machine, then put the vise in this base to do some inspection work perhaps, then put it back on the machine clamp in the machine still be in the same location on the machine (within about .005"). This would allow a machinist to be able to do several machining operations without ever taking the part out of the vise. This base is designed to bolted down to a flat surface, or bolted on a sub-plate, and their are 3 holes provide in the base flange for that. The T-handle on the side is a cam locking lever that holds keeps the upper section from rotating. The vice shown in the pictures is not included, but we generally have them in stock and listed for sale on this website. This base is about 4" high x 4.5" diameter base plate. It is machined flat and is in very good condition, no rust, very little wear, good threads and hardware. We note the the wrench that tighten the swivel base down, it not original as it is a bit longer than the original was, and is marked "LITTLE DAVID" on the underside of the handle. The wrench fits the nut correctly, and the adjustment works just fine. A rare and handy tool!