Precision JO-PLUG® pitch diameters are calibrated using a Pratt & Whitney Super Mic utilizing the universal "three-wire method."


Precision JO-PLUG® "lead and trail" thread angles are verified using a J&L Metrology Optical Comparator.

We are proud to have Leader Corporation of Shelby Township, MI as our precision thread grinding source. Leader also acts as our third-party ISO/IEC 17025:2017 accredited partner for inspection and dimensional calibration of Precision JO-PLUGS®.
A2LA Accreditation # 3692.01