Starrett 234MA-50 End Measuring Rod with Spherical End and Insulating Handle, 6.3mm Diameter, 50mm Length

The rod or "standard" is for checking and setting micrometers of 2" capacity and larger, and are also used on machine tools for comparing gauges, checking precision measuring tools, for measuring parallel surfaces, and many other types of work. It is made of special tool steel in rod form with ends hardened and accurately lapped to a spherical radius. Available with insulated handle to minimize expansion by heat when held in the hand.