We hold one of the largest inventories of Hardness Standards in the industry. Our certified Hardness Standards are used to easily verify every level of performance and accuracy of hardness testing equipment and indenters. Sun-Tec Hardness Standards are known for their outstanding accuracy, uniformity, and consistency. Manufactured in the USA by Sun-Tec Corporation, they meet all applicable ASTM specifications and are calibrated in our ISO/IEC 17025 accredited standardization lab. A complete list of standards can be found on our accessories page.