JBO Thread Ring Gauge (GO) - UNF - Right Hand - 3A - No. 6 x 40 Tapping Chucks this reamer achieves ISO H4

this reamer achieves ISO H4 tolerance for consistent bore sizes across common materials

while the tight DIN 212-B tolerance keeps hole sizes consistent across parts

Carbide construction for long tool life: High‑hardness carbide delivers exceptional wear resistance

This gauge helps streamline inspections

JBO Thread Ring Gauge (GO) - UNF - Right Hand - 3A - No. 6 x 40 Tapping Chucks this reamer achieves ISO H4The JBO Thread Ring Gauge (GO) UNF Right Hand 3A No. 6 x 40 is a precision inspection tool designed to verify external thread diameters on UNF right hand threads. Used by engineers, inspectors, machinists, and quality teams, it provides a clear, reliable check to confirm components meet the required GO standard before assembly or shipment. Crafted from hardened steel for lasting durability, this ring gauge stands up to daily use in busy workshops and