Precision Steel Square Gauge Block Single solid steel block available sizes for accurate measurement and setup. for Lathe and Milling Tools for parallel alignment, squaring, and setup tasks in lathe work, milling, and inspection. Made from Hardened Tool Steel Crafted from wear-resistant steel for long-term durability and dimensional stability under frequent use. Ground Flat and Parallel Block is precision ground to tight tolerances for consistent performance and reliable reference. Versatile Use in Workshop Suitable for layout, calibration, and fixture setup in machining, metalworking, and toolmaking environments.