The acme thread shape has a wider base than other thread forms, which means it offers greater strength, as the screw can support a heavier load. This, therefore, means the vice can hold large and heavy workpieces with less risk of the screw breaking.
This thread form also allows the use of a split-nut which is ideal for manufacturing vices with a quick-release mechanism.
The screw is held in place within the vice’s body by a nut, which keeps the screw static once the jaws are closed around a workpiece. The end of the screw is attached to the vice handle which controls the screw’s movement.