Precision meets reliability with the SPI Rectangle Steel Gage Block. This 0.13" Grade AS-1 gage block is an essential tool for dimensional measurement and calibration applications. Manufactured to exacting standards by SPI, this rectangular steel block provides consistent, accurate measurements for quality control processes. Each block comes with NIST Certification, ensuring traceability and compliance with national measurement standards. The durable steel construction offers excellent wear resistance and dimensional stability over time, making it ideal for industrial inspection departments, tool rooms, and precision manufacturing environments. Part #15-044-1 is designed for professionals who demand unwavering accuracy in their measurement tools. Use it individually or as part of a set to verify measuring instruments, set up machinery, or establish reference dimensions for critical components.