Product details:
The Brown & Sharpe 599-750-10 1-2-3 blocks set includes a pair of 1' x 2' x 3' blocks, five 3/8-16 stainless steel socket head cap screws, and a hex key. The steel blocks offer rigidity and stability, and are oversized to allow normal tapping from .0001' to .0003'. With 28 holes, including five tapped 3/8-16, the blocks allow a range of different uses. Each block is ground and case-hardened to 50 to 60 Hardness Rockwell C (HRC) on all six surfaces, making all sides equally usable, and features squareness on all sides to .0001'. The surface finish is 6 to 16 microinches. Blocks are used to check the squareness of machine fences, table saw blades, drill press chucks, and any other 90-degree angle found in industrial shops. Due to their weight, they are unlikely to inadvertently shift while in use. The holes can be used as stop blocks and make them easy to attach to drill press tables and table saw jigs. They can be used as a square for applications under 3 inches.