The pipe clamp is what many people think about when they think clamps for woodworking. They are exceptionally affordable - you buy the a set of clamping fixtures (head & tail piece), then attach them to a length of iron black pipe. Clamping fixtures are available to fit 1/2 inch & 3/4 inch black pipe, something to remember is that pipe is sized by its inside diameter (size of hole) not the external dimension. Clamping fixtures for black pipe offer versatility, as clamp capacity is only limited by the length of pipe you select. It takes very little time to move the clamping fixtures from one pipe to another. Features ACME threaded spindle & multiple clutch plates. They are easy to assemble & incredibly durable; however, the soft pads can become worn or lost & these packages of replacement pads are inexpessive so there is no excuse for doing without. BESSEY. Simply better.