Niigata Seiki SK Made in Japan Steel Ring Gauge 6.7mm RG-6.7

Master of internal diameter measuring instruments. All products are sub-zero treated, stabilized, and wrapped. The ring gauge is used for 55-point adjustment as a master gauge for hole tests, cylinder gauges, inner micrometers, dial calipers, inner diameter measuring instruments, inner dial comparators, etc. Material: Alloy tool steel Nominal dimension (mm): 6.7 Circularity (μm): 0.5 Cylindricity (μm): 0.5 Inner diameter tolerance (μm): ±1.0 Hardness (HV): 653~772 Outer diameter d (mm): 32 Thickness B (mm): 8・Outer diameter chamfer *C (mm): 0.8・Inner diameter chamfer *F (mm): 0.5・Notes: With knurling