Ground and hardened on all sides for use with any machine tool, delivering long wear resistance and a stable reference surface. Hexahedron (six-faced) block made of hardened steel provides rigid, true faces for repeatable setup and alignment. Designed for setup, layout and inspection tasks, helping improve accuracy and reduce setup time. High precision milling parallel clamping block with accuracy up to .0001 in. §23 holes include (5) 3/8-16 threaded holes for clamping and (18) unopened holes for versatile fixturing. Use scenarios - Setting up a workpiece on a milling machine to achieve parallelism and accurate datum positioning. - Laying out features on a part before machining, using the threaded holes for secure clamping. - Creating an inspection fixture to position a part consistently for measurement checks against datum faces. Material: hardened steel Function: setup, layout, inspection Compatibility: suitable for all machine tools Size: hexagonal block with §23 holes (5 threaded, 18 unopened) Performance: high precision tolerance up to .0001 in