Roundness Master Calibration Spheres for calibration of roundness measuring machines are available with high quality long wearing tungsten carbide spheres. The .500 inch (12.7mm) sphere is round to less than 2.5 micro inches (50.8 nm). This flange mounted master sphere can be used on all roundness measuring machines.
See: Technical Data Sheet AUT-6

Part #	Description	Price	Purchase
AUT-MS.5	ROUNDNESS MASTER CALIBRATION SPHERE	$720.00