JBO Thread Ring Gauge (GO) - Metric Fine - Right Hand - 6g - M21 x 1 4 Month Widin Four-flute carbide with precise corner

Four-flute carbide with precise corner radius: The four-flute configuration allows efficient material removal and a refined finish at corner radii

designed to produce clean bores to ISO H5 tolerances

This taper shank reamer uses HSS (M2) steel and features a left-hand spiral flute with right-hand cutting for stable

Left‑hand spiral flute with right‑hand cutting: Delivers efficient chip removal and predictable cutting action for smooth finishes

20 mm bore with ISO H4 tolerance

JBO Thread Ring Gauge (GO) - Metric Fine - Right Hand - 6g - M21 x 1 4 Month Widin Four-flute carbide with precise cornerThe JBO Thread Ring Gauge GO Metric Fine, Right Hand, 6g, M21 x 1 is a precision inspection tool designed to verify external thread diameters on fasteners, connectors, and machined parts. Its ideal for engineering shops, quality control teams, maintenance crews, and seasoned hobbyists who need fast, reliable pass fail checks to ensure parts meet required standards. Crafted from hardened steel for durability and wear resistance, this GO gauge delivers