Work holding devices securely and accurately position workpieces on a milling table. Vises are the most common devices used in milling.

The light coat of rust preventative such as Boeshield T-9 or LPS-3 is recommended prior to mounting. Parallel alignment of the fixed vise to the X-axis is accomplished with a dial test indicator. This vise is out of alignment by 4 thousandths of an inch per 6 inches. With the bolts partially tightened, the vise can be manually bumped into near perfect alignment. Some vises can be mounted lengthwise along the table or sideways for holding workpieces vertically.

Parallels are used to elevate the workpiece giving clearance for side milling and through-hole drilling. Thin parallels as well as wavy parallels are used for thinner workpieces. Jaw plates in the outboard positions of the vise jaws allows clamping of large plates. Double-station vises hold 2 workpieces for added productivity.

Vee blocks hold cylindrical workpieces and can quickly and accurately locate the Y-axis center. The v-block can also hold round bars vertically or other work holding devices such as collet chucks. A vise can be held within another vise as demonstrated with this sine vise.

Step clamps are easily adjustable in height for mounting workpieces directly to the T-slot table. Care should be taken to ensure the clamp is parallel to the surface of the table and not tilted. The possibilities are limitless. In this example, a lathe chuck is used to hold a large tubular steel workpiece.