This T-Slot Fixture beats the pants off a regular mill vise! The Invert-A-Bolt™ Universal Stock Prep Fixture* is ideal for prepping or machining stock material. The Stock Prep fixture is similar to a mill vise but with several advantages: being able to accept larger stock sizes, having greater holding power, the ability to drill through without damaging the fixture, positive location in either axis, a fixed zero location for the stock material. Stock greater than .530" thick can be faced without collision with the fixture. It is constructed from Grey Cast Iron, ASTM Class 40 or as specified by the customer. These fixtures work great either as stand alone fixtures or as stock prep components on the tombstone.