JBO Thread Ring Gauge (NoGo) - Metric Fine - Left Hand - 6g - M21 x 1 Milling Cutter Arbors and extend tool life during

and extend tool life during heavy-duty milling

and a trusted solution that fits standard tooling systems

85 mm nominal diameter and a taper shank

making it a dependable choice for precise hole finishing in metalworking projects

and other applications that require clean

JBO Thread Ring Gauge (NoGo) - Metric Fine - Left Hand - 6g - M21 x 1 Milling Cutter Arbors and extend tool life duringThe JBO Thread Ring Gauge (NoGo) Metric Fine Left Hand 6g M21 x 1 is a precision inspection tool designed to verify external thread diameters on components with metric fine threads. Built for engineers, buyers, tradespeople, hobbyists, and quality teams, it helps confirm that threaded parts meet exact diameter limits at a glance. Crafted from hardened steel for durability, this NoGo ring gauge withstands daily use in busy workshops, garages, and