Palmgren's Angle Sine vises are built for ultra precision grinding and inspection applications of small parts. Solid one-piece body, precision ground and heat treated to 55 HRC then tempered to ensure stability and durability. Screw type moveable jaw. Top, sides, and bottom are precision ground square and parallel. Parallelism: 0.0004" and Squareness: 0.0004" Minute angle steps allows very small angles to be set with ease using standard gauge blocks.