Threading Technology – Clamping Technology 520

474 Thread Gages UNC UNF UNS M MF Rp, R, Rc NPT NPTF STI SELF-LOCK G (BSP) Product Finder Smooth GT, TD Accessories Calibration Tech. Info 6.7 Gaging of other threads Thread gages for other threads (sealing threads, tapered threads, threads for tight fit, SELF-LOCK threads etc.) often deviate considerably from the normal gage design. They are usually adjusted to the special design and function of these threads. One good example are the thread gages for sealing threads, e.g. NPT and NPTF threads acc. US standards, or pipe sealing threads acc. DIN EN 10226 / ISO 7. In such cases, the instructions for the gaging of these threads must be observed in every detail. 6.7.1 The gaging of the EMUGE SELF-LOCK thread We recommend using our two-piece gage system which corresponds to the usual combination of GO and NO-GO gage and is perfectly sufficient for the gaging of the thread, provided that the SELF-LOCK threads were produced with our true-to-profile EMUGE taps. There is no generally applicable standard (e.g. DIN standard) for the EMUGE SELF-LOCK thread, so other manufacturers may use different limit sizes for their threads. For this reason, we recommend gaging EMUGE SELF-LOCK threads exclusively with EMUGE SELF-LOCK gages. With the GO plug gage, it is important to observe the correct screw-in direction. The NO-GO side can be used in either screw-in direction. GO/NO-GO plug gage for the EMUGE SELF-LOCK thread < 36 T.P.I. (P > 0.7 mm) Whenever threads are produced by chasing or thread milling, we recommend the additional use of our EMUGE HRPG gage which checks the lower end of the ramp, and helps to identify any deviations in the angle of the ramp. HRPG NO-GO plug gage for the EMUGE SELF-LOCK thread < 36 T.P.I. (P > 0.7 mm) The gaging of the buttress profile works on the same principle, with the only difference that both the GO and the NO-GO plug gage have to be used in the correct direction. GO/NO-GO plug gage for the EMUGE SELF-LOCK buttress thread ≥ 36 T.P.I. (P ≤ 0.7 mm) 6.7.2 American Pipe Thread, thread angle 60° 6.7.2.1 Pipe thread for general applications (with sealant) according to ANSI/ASME B1.20.1 Overview: NPT NPSC NPTR NPSM NPSL NPSH Each letter in the designation has the following meaning: N National (American) Standard P Pipe T Taper C Coupling S Straight M Mechanical L Locknut H Hose coupling R Railing fittings The thread profile is symmetrical and perpendicular to the thread axle! NPT thread • Tapered internal thread and external thread • Tapered plug gages L 1 with 3 measuring steps (Min., Basis, Max.) • Tapered ring gages L 1 with 3 measuring steps (Min., Basis, Max.) NPSC thread • Cylindrical internal thread for pressure-tight connections, is screwed with a tapered external thread NPT and an additional sealing • Tapered plug gages L 1 mit 3 measuring steps (Min., Basis, Max.) NPTR threads • Tapered internal thread and external thread for the rigid mechanical screwing of railing fittings (similar to NPT). NPSM thread • Cylindrical internal and external thread for mechanical “Free-Fitting” connections and fastening primarily of pipes without internal pressure • Ring gages and plug gages GO and NO-GO are cylindrical! NPSL thread • Cylindrical internal and external thread for mechanical “Loose-Fitting” connections with locknut, e.g. through container walls and tightened with locknuts on both sides • Ring gages and plug gages GO and NO-GO are cylindrical! NPSH thread • Cylindrical internal and external thread for mechanical “Loose-Fitting“ connections of hose couplings • Ring gages and plug gages GO and NO-GO are cylindrical!