The thread plug gauges for BSPT ISO 7 R taper pipe threads are inspection tools designed to verify the conformity of internal tapered threads intended for connection with tapered Gas pipe threads according to ISO 7. They are used for checking fittings, valve bodies, hydraulic components, pneumatic parts, fluid power elements, manifolds, adapters and mechanical components where sealing performance depends on the correct tapered thread geometry and compatibility between male and female threads.

BSPT ISO 7 R taper pipe threads use a 55° Whitworth profile and a 1:16 taper, allowing progressive engagement between threaded components. Unlike BSPP / ISO 228 G parallel pipe threads, tapered threads can contribute to sealing through progressive thread interference, often combined with sealants, tapes or dedicated sealing compounds depending on the application. For this reason, checking engagement depth, taper, profile and thread position is essential to ensure correct assembly, connection safety and reduced risk of leakage.

The hardened steel construction with 58 HRC ±2 hardness provides high wear resistance, dimensional stability and long-term reliability, even in production departments with repeated inspection cycles. The high manufacturing quality of the gauges supports accuracy and repeatability during inspection, reducing the risk of accepting out-of-tolerance threads or rejecting conforming components. The gauge geometry provides a practical reference for quickly checking the correct execution of tapered threads in production, inspection and maintenance environments.

The correct gauge must be selected according to nominal R size, ISO 7 standard, associated thread pitch and required inspection function. It is important to correctly distinguish gauges for BSPT / ISO 7 R taper pipe threads from gauges for BSPP / ISO 228 G parallel pipe threads, because taper, connection method, inspection depth and sealing function are different.

During use, the gauge must be screwed in carefully, kept coaxial with the threaded hole and not forced beyond the specified inspection point. The thread to be checked must be clean from chips, burrs, oxides, dirt or machining residues, as contamination or surface defects may affect inspection feel and damage the gauge. Misaligned or forced use can compromise both the gauge and the inspected component. These thread plug gauges are suitable for quality control, mechanical workshops, fitting production, industrial maintenance, inspection departments, CNC machining, hydraulics, pneumatics and fluid power applications where repeatable verification of BSPT taper pipe threads is required.