JBO Thread Ring Gauge (GO) - UNC - Right Hand - 2A - No. 4 x 40 Milling Cutter Arbors producing superior surface finish and

producing superior surface finish and tight dimensional accuracy with minimal finishing work

finished with a hard

accurate hole finishing in demanding metalworking tasks

this reamer delivers repeatable hole sizes

helping operators maintain tolerances

JBO Thread Ring Gauge (GO) - UNC - Right Hand - 2A - No. 4 x 40 Milling Cutter Arbors producing superior surface finish andThe JBO Thread Ring Gauge (GO) for UNC external threads is a precision inspection tool designed for machinists, quality teams, and assembly technicians. Sized for No. 4 x 40 with a right hand thread and 2A class accuracy, it enables fast, reliable verification of external thread diameters to UNC standards. Whether youre on a production line, in a workshop, or in a quality lab, this GO gauge helps confirm that parts will thread correctly and assemble