_Suitable for threaded screws, fittings. Suitable for turning parts, socket wrench, Bits. Possible to measure from both side, add V anvil for straightness measurement. Comply with ISO4759-1 and ANSI/ASME Y14.5M(GD&T) geometric dimensioning and tolerancing Roller accuracy: within 3u, Roller material: SKS3, Roller hardness 60HRC