A metalworking vise (sometimes spelled vice) has two parallel jaws that clamp together to hold an object in place.
How do metalworking vise jaws work?
One jaw is stationary and attached to the main body of the vise. This provides additional stability.
The other jaw moves, this dynamic jaw is moved towards or away from the stationary jaw via a lead screw. The lead screw is turned by rotating a handle. The handle provides mechanical leverage and allows you to clamp with great force. Many lead screws are hidden inside a case or slide to improve the longevity of the screw – you don’t want debris gunking up the screw threads.
The lead screws are usually made with acme threads. These threads have a trapezoidal structure, meaning the sides of the thread are at an angle rather than perpendicular. Acme threads work great for vises as they don’t need breaks to hold a position, and they don’t need as much lubrication. Acme screws are a great way to turn rotational movement (the vise handle) into linear movement (the moving vise jaw).
The jaws themselves are usually made of ridged or serrated hardened steel. As a general rule, hard materials scuff up soft materials. A hardened steel vise jaw allows the vise to handle hard materials without excessive wear and tear. These jaw are replaceable and are held in place by two screws on most models of metal working vises.
Other Information on how metalworking vises work
The body of a metalworking vise is usual made out of grey cast iron or ductile cast iron. You can find some models with forged steel bodies. These materials provide weight and support to the vise jaws. You can find more information on the materials of a metalworking vise jaw in my article what are vises made of?
Most metalworking vises must be bolted to a table. This is because this type of vise tends to be heavier and needs more support.
You can find smaller vises that have c clamps underneath the base of the vise, these clamp to the table rather than get bolted. Clamp vises are very common for jewelry vises and woodworking vises, but are less common for metal working vises.
And that’s pretty much it. Vises are not a complicated tool. Bolt it to the table, turn the handle to open and close the jaws, and you are done. They can be a big investment however, especially if you are getting a big shop vise that can handle a wide variety of work loads. If you are feeling hesitant as to to which vise to buy, check out my guide to the best 3 bench vises.