Taper gauges (NPT) — detail
Gauge family 04 / 11

NPT thread plug & ring gauges, manufactured in Pune.

ANSI/ASME B1.20.1National Pipe Taper (NPT) · ANSI / ASME B1.20.1

An NPT thread gauge checks National Pipe Taper threads to ANSI/ASME B1.20.1. Because NPT threads seal by the taper, they are checked with a basic or min/max step gauge instead of a parallel GO / NOT-GO pair. Accusize manufactures NPT gauges in Pune.

NPT taper thread gauges manufactured to ANSI / ASME B1.20.1. Our expertise also covers non-standard designs: extra lengths, air grooves, pilots and depth steps.

Ring gauges
Basic & min/max step
Plug gauges
Basic & min/max step
Representative sizes & classes
MemberTypeAcceptance
External threadBasic step ringFlush within a single turn
External threadMin/max step ringFace between min & max step
Internal threadBasic / min-max plugFlush within limits

External threads: when screwed on by hand, the basic step gauge should be flush with the component face within a single turn. Internal threads: with a min/max step gauge, the component face should sit flush between the minimum and maximum step limits.

Ground on our Matrix thread grinders and verified on TRIMOS H4 before every certificate is issued.

About this gauge

Taper gauges (NPT): what they are and how to choose

On an external NPT thread, the basic step ring gauge should sit flush with the component face within a single turn when screwed on by hand. On an internal thread, the face should sit between the minimum and maximum step of a min/max plug gauge.

Non-standard NPT designs with extra lengths, air grooves, pilots and depth steps can be made to drawing.

Each gauge ships with a NABL accredited test certificate. We supply across India and take enquiries from outside India.

Common questions

Questions about Taper gauges (NPT)

What are taper gauges (NPT)?

An NPT thread gauge checks National Pipe Taper threads to ANSI/ASME B1.20.1.

Which standard does it follow?

Manufactured to ANSI/ASME B1.20.1.

What range is available?

Available ranges: Ring gauges Basic & min/max step; Plug gauges Basic & min/max step.

How is acceptance checked?

On external threads, the basic step gauge should sit flush with the component face within a single turn when screwed on by hand. On internal threads, the component face should sit flush between the minimum and maximum step limits of a min/max step gauge.

Is an NPT gauge the same as an NPTF gauge?

No. NPTF is the dry-seal version of the thread and has its own standard, ANSI/ASME B1.20.5, and extra gauge members. See our NPTF and ANPT gauges.

Is NPT the same as BSPT?

No. NPT has a 60° thread angle and BSPT has a 55° angle, so each needs its own gauge.

Do you supply outside Pune?

Yes. We supply across India and take enquiries from outside India too. See the where we supply page for details.

How do I request a quote?

Share the thread size and standard on our quote page and we will confirm class, availability and pricing within one business day.

Related

Other gauge families

“G” pipe gaugesNPTF & ANPT gaugesTaper pipe threads
Taper thread gaugesGauge manufacturer in IndiaHow a GO / NOT-GO Thread Gauge WorksMetric vs Unified vs Pipe and Taper ThreadsWhat Is a Thread Gauge? Types and UsesNPT vs BSPT vs G Pipe ThreadsNPT vs NPTF: Dry-Seal Threads ExplainedOil & gasPumps & valves

Need taper gauges (npt)?

Share your thread, standard or drawing and get the right acceptance class, certified. We supply across India and take enquiries from outside India too, see where we supply.