Roundness Testers. Roundness Measuring Instruments The machine reference table and Z-axis column material are made of natural granite, the structure is not deformed, and the performance is more stable and reliable. The rotating spindle adopts a frictionless air-floating spindle, the accuracy is kept longer, and the rotation speed is stable. The use of X-direction and Z-direction high-precision grating sensors improves the degree of automation and realizes the measurement function that the sensors can automatically contact The key components adopt special stress-relief alloy materials and special stress-relief treatment process, and the durability and accuracy are kept longer. Contact. www.salbroengineers.com