JBO Gauges.
Precision You Can Measure.
JBO (Johs. Boss GmbH & Co. KG) has been manufacturing precision thread gauges and cutting tools in Germany for over 175 years. Protool is proud to stock the full JBO gauge range — plug gauges, ring gauges, and all major thread forms.
Shop JBO Gauges →Shop JBO Thread Gauges
Browse the full JBO thread gauge range at Protool — plug gauges, ring gauges and all major thread forms, all stocked and ready to ship.
Gauge Types
Double-ended plug gauges for efficient Go/NoGo checking in a single tool.
→GO plug gauges — verify that a threaded hole is within the minimum acceptable limit.
→Combined Go/NoGo plug gauges for fast, complete thread inspection in one pass.
→NoGo plug gauges — confirm that a threaded hole does not exceed the maximum limit.
→GO ring gauges — verify that an external thread is within the minimum acceptable limit.
→Combined Go/NoGo ring gauges for complete external thread inspection.
→NoGo ring gauges — confirm that an external thread does not exceed the maximum limit.
→Thread Forms Available
Over 175 Years of German Precision
Johs. Boss GmbH & Co. KG (JBO) is a German precision tool manufacturer with over 175 years of heritage in producing high-quality thread gauges and cutting tools. With deep expertise in thread measurement and quality assurance, JBO gauges are trusted by engineers and quality engineers in demanding industries worldwide.
At Protool, we stock the JBO thread gauge range — covering both plug and ring gauges across all major thread forms, from Metric and BSP through to NPT, UNC, UNF and specialist forms. Whether you need GO, NoGo or combined Go/NoGo gauges, we have them in stock and ready to ship.
The Complete Thread Gauge Solution
JBO plug gauges check internal threads — available as GO, NoGo, or combined Go/NoGo (D/E double-ended) for fast, efficient inspection on the shopfloor or in the quality lab.
JBO ring gauges check external threads — GO, NoGo, and Go/NoGo formats available across all major thread standards for complete external thread verification.
Full coverage of Metric, BSP, BSPT, BSW, BSF, UNC, UNF, UNEF, UNJC, UNJF, UNS, NPT, NPTF, Pg, Trapez, and Electrical Conduit thread forms.
JBO also supplies gauges for STI (Screw Thread Insert) thread forms — Metric STI, UNC STI, and UNF STI — for checking threads designed to accept Helicoil inserts.
JBO has been manufacturing precision gauges in Germany for over 175 years — a heritage of quality and accuracy that makes them one of the most trusted gauge brands in the world.
We hold JBO gauges in UK stock for fast despatch. Need help identifying the right gauge for your thread form and tolerance class? Our team is on hand to advise.
Ready to order JBO Gauges?
Browse the complete JBO thread gauge range at Protool — plug gauges, ring gauges and all major thread forms, stocked and ready to ship.
View All JBO Gauges →JBO Thread Gauges — Precision Thread Measurement from Johs. Boss GmbH
JBO (Johs. Boss GmbH & Co. KG) is a leading German manufacturer of precision thread gauges and cutting tools, with over 175 years of manufacturing heritage. JBO thread gauges are used by quality engineers and machinists worldwide to verify that threaded components meet precise dimensional tolerances.
Protool stocks the JBO thread gauge range including plug gauges and ring gauges across all major thread forms. Plug gauges are used for checking internal threads — available as GO gauges (checking the minimum limit), NoGo gauges (checking the maximum limit), and combined Go/NoGo double-ended plug gauges (D/E) for efficient inspection in a single tool.
Ring gauges are used for checking external threads — again available in GO, NoGo, and combined Go/NoGo formats. Together, JBO plug and ring gauges provide complete thread inspection capability for both internal and external threads.
The JBO gauge range covers an exceptionally wide variety of thread forms including Metric, BSP (G), BSPT (R), BSF, BSW, Electrical Conduit, NPT, NPTF, Pg, Trapez, UNC, UNF, UNEF, UNJC, UNJF, UNS, and STI (Screw Thread Insert) variants including Metric STI, UNC STI, and UNF STI for threads designed to accept Helicoil-type thread inserts.
JBO gauges are manufactured in Germany to exacting tolerances and are suitable for use in quality control environments across aerospace, automotive, oil & gas, medical, electronics and general engineering. All gauges available from Protool are genuine JBO products, stocked in the UK for fast despatch.
