JBO Thread Ring Gauge (GO) - UNC - Left Hand - 2A - 1 x 8 M&D 2 and a 6 mm

2 and a 6 mm diameter

The rugged construction minimizes downtime and maintenance

helping you reach exact dimensions with minimal chatter

maintaining hole size and finish across multiple parts

The multi‑flute configuration accelerates material removal while aiding chip evacuation to keep heat in check

JBO Thread Ring Gauge (GO) - UNC - Left Hand - 2A - 1 x 8 M&D 2 and a 6 mmThe JBO Thread Ring Gauge (GO) for UNC left hand threads is a precision inspection tool designed to verify external thread diameters with consistency. Ideal for machinists, quality technicians, engineers, and shop floor personnel working with UNC left hand 1 x 8 size, it provides fast, reliable go no go checks to ensure parts meet the specification. Specifically calibrated for UNC left hand 1 x 8 size: Provides a precise go no go reference for