Precision meets reliability with the SPI Rectangle Steel Gage Block measuring exactly 0.145 inches. This Grade AS-1 gage block delivers exceptional dimensional accuracy for your most demanding measurement and calibration tasks. Each block comes with NIST Certification, ensuring traceability and compliance with national measurement standards. Manufactured by MSC Industrial under the trusted SPI brand, this rectangular steel gage block provides the consistent reference surface needed for precise instrument calibration, machine setup, and quality control inspections. The durable steel construction offers excellent wear resistance and dimensional stability over time. Perfect for metrology labs, manufacturing facilities, and quality assurance departments where accurate measurements are critical to operations. Part #15-059-9 represents SPI's commitment to providing industry-standard measurement tools for professionals who demand nothing less than excellence.