Big Horn 19301 Heavy Duty Cast Iron Pipe Clamp. A perfect holding tool for woodworkers working on cabinets and wooden boxes! Easy to use and convenient, just slide the pipe clamp through any length 3/4" pipe to hold wood in place for gluing and drilling. Constructed of tough cast iron that keeps wood steady as you work, this clamp is a great addition to any woodworking work bench at the home or shop!