JBO Thread Ring Gauge (GO) - Metric Fine - Left Hand - 6g - M21 x 1 Tapping Chucks The taper shank design fits

The taper shank design fits standard fixtures securely for reliable alignment

repeatable toolholding across jobs and minimizes variation in part quality

this reamer helps you finish pre-drilled holes with high concentricity and a precise finish

Flute Design: Spiral flute promotes efficient chip evacuation and smooth cutting action

and other small components where a standard fixed-bore collet doesn’t provide the exact tolerance you need

JBO Thread Ring Gauge (GO) - Metric Fine - Left Hand - 6g - M21 x 1 Tapping Chucks The taper shank design fitsThe JBO Thread Ring Gauge (GO) Metric Fine Left Hand 6g M21 x 1 is a precision tool designed to verify external thread diameters on fasteners, fittings, and machined components. It is ideal for engineers, machinists, quality inspectors, and workshop technicians who need fast, reliable go no go checks to ensure threads meet their exact specifications. Crafted from hardened steel with a knurled exterior for secure handling, this GO gauge delivers