(R) 81PCS Grade B Gage Gauge Block Set - High-Quality Calibration Tool for Precision Measurement

Features 81-Piece Set]: Includes 81 pieces, consisting of blocks in various sizes ranging from 0.1001" to 4" [High-Quality Material]: Made of fully seasoned alloy tool steel and hardened to 65 RC, providing long wear and resistance to stains and rust [Accurate and Reliable]: Blocks manufactured under carefully controlled conditions for the highest degree of accuracy when used at room temperatures of 68 degrees F (20 degrees C).

Accuracy unit: millionths of an inch (uinch) [Certified and Serialized]: Certified by an accredited ISO-17025 Gage lab with long form certification and individual serial numbers on each block, regardless of grade [Versatile Application]: Ideal for use in calibration, inspection, and dimensional metrology applications, as well as in the inspection and testing of precision instruments.