Today’s vises range in configuration from relatively simple single-station models to very elaborate multiple-station designs. Most vises consist of a mounting base or body that is secured to the machine table, a stationary jaw against which part material to be machined is located, a movable jaw and screw mechanism.
When tightened, the movable jaw is pushed or drawn forward by the screw mechanism thus clamping the workpiece against the stationary jaw.
Vises are simple, relatively fast and easy to operate. Their advancements were greatly accelerated in the 1960s with the advent of CNC machines when the demand for higher precision parts and greater productivity gave birth to a patented precision machine vise. Early vise designs, when under pressure, deflected so that part alignment was a constant problem.
The precision machine vise, with its friction reducing, needle bearing, thrust collar, aligned and held parts more accurately and securely than any previous screw type vise.
Double-station, multiple-station, self-centering, hydraulic, vertical and many other versions were developed out of the basic concept of the original single-station, precision machine vise.
To address the workholding needs of a particular machining operation, one needs to consider part size, material, machine speed, feedrate and the quantity of parts to be produced. Process planning requires dividing the machining process into steps best suited to the available machines. Smaller machine shops are more likely to plan their workholding around knee mills or VMCs.
With knee mills, the full range of vise accessories can help with setup reduction, such as quick change jaws, which, in some cases can reduce changing jaw plates to just 5 percent of the previously required time. For more complex machines—HMCs and VMCs—part loading time and setup are an integral element of downtime and need significant attention to maintain high efficiency. Workholding again becomes a central element in maximizing machine uptime.
Following are considerations for maximizing productivity using vises on frequently encountered machining situations:
Vise selections and their characteristics (number of stations, parts per station, means of actuation, etc.)
Jaw plate considerations and its effect on part contact and repeatability
Locating systems for setup reduction and position accuracy
Workstop systems
Helpful accessories to make the clamping job easier
Metalworking vises, also called engineer’s vises, hold pieces of metal in place instead of wood, in order to file and cut them. These vises are sometimes made of cast steel but are mainly made of cast iron. Some have a cast iron body with a steel channel bar. Cast iron is a popular material to use because it is rigid, strong, and inexpensive. The jaws are often a separate piece so that they’re replaceable. Soft jaw covers may be used to protect delicate work, and are made of aluminum, copper, wood, or plastic. They are often bolted onto a workbench, with the face of the jaws jutting out a little over the front edge. These vises may also have a small anvil on the back of their bodies, and most have a swivel base.
vise, also spelled Vice, device consisting of two parallel jaws for holding a workpiece; one of the jaws is fixed and the other movable by a screw, a lever, or a cam. When used for holding a workpiece during hand operations, such as filing, hammering, or sawing, the vise may be permanently bolted to a bench. In vises designed to hold metallic workpieces, the active faces of the jaws are hardened steel plates, often removable, with serrations that grip the workpiece; to prevent damage to soft parts, the permanent jaws can be covered with temporary jaws made from sheet copper or leather. Pipe vises have double V-shaped jaws that grip in four places instead of only two. Woodworking vises have smooth jaws, often of wood, and rely on friction alone rather than on serrations.
For holding workpieces on the tables of machine tools, vises with smooth hardened-steel jaws and flat bases are used. These machine vises are portable but may be clamped to the machine table when in use; means may also be provided for swivelling the active part of the vise so that the workpiece can be held in a variety of positions relative to the base. For holding parts that cannot be clamped with flat jaws, special jaws can be provided.