A bench clamp is a temporary device designed to hold work securely in place on a workbench. Bench clamps are used in everything from carpentry and woodworking to furniture making, welding and metal working. Multiple bench clamp styles are available, depending on the task; they include: C-clamps, bar clamps, pipe clamps, handscrews, vises, bench dogs and hold-downs.
Designed in the shape of the letter C, a C-clamp holds things firmly together and is adjustable depending on the throat or reach of the clamp. It is usually made of cast iron or steel. The clamp is used by turning a screw through the bottom of the C frame until the work piece is fully stabilized. Clamps range in size from 3/4 inch to 12 inches (1.9 cm to 30.48 cm).
Similar to a C-clamp, a bar clamp has a fixed end with a jaw and an adjustable end. Some bar clamps include a disk clutch within the sliding jaw that allows you to place the clamp anywhere along the bar. This lets the user make quick adjustments and allows a strong hold. Bar clamps range from 6 inches to 6 feet (15.24 cm to 1.82 m) in length.
A pipe clamp, which is also known as a gluing clamp, uses a 1/2-inch (1.27 cm) or ¾-inch (1.90 cm) pipe fastened into a fixed jaw. The jaw installed on the opposite end of the pipe is both adjustable and can be moved from its original position. The work piece is held against the adjustable jaw and the crank is tightened to secure it. The length of pipe used in making the clamp determines its capacity.
For work pieces with unparallel sides, handscrews are used. Handscrews consist of two screws, one with a left-hand thread and one with a right-hand thread. The screws pass through an extended opening so the jaws can be engaged in a non-parallel position.
A bench vise entails a fixed jaw and a parallel jaw that can be adjusted by screw mechanism. A clamp-on bench vise is a portable vise that can be clamped on or screwed into a workbench. A vise enables the work piece to be held fast while other work, such as sanding, sawing, drilling, screwing, planing, etc., is performed on it.
Bench dogs are effective in holding flat stock in place for belt sanding and hand planing. They are inexpensive and generally come in packs of four. Hold-down clamps may be used to wedge the work piece against the bench. Some workbenches include built-in adjustable clamps. These often are portable and fold down for easy storage.