A hand screw clamp is available in 12 different sizes. With any clamp, the most important size dimensions to consider are the width of its jaw opening and the depth of its throat. In terms of hand screw clamps, a user can also consider the length of its jaw, when determining whether it is large enough to clamp a particular workpiece.
Jaw length
The jaw length is the total distance along the jaw edge. However, the usable jaw length is measured by the distance along the jaw edge from one end to the position of the inner screw.
The shortest jaw length is 100mm (4″ approx.) and the longest, 610mm (24″ approx.).
Jaw opening
The jaw opening indicates how far the mouth of the jaws can open.
The smallest jaw opening is 50mm (2″ approx.) and the largest, 430mm (17″approx.).
Throat depth
The throat depth is how deep the jaws of the handscrew clamp are, and is measured by the distance from the edge of the jaw to the spindle.
The smallest throat depth is 50mm (2″ approx.) and the largest, 300mm (12″ approx.).
