NPT plug gageNPT ring gage

NPT thread gages manufacturer / supplier

NPT thread plug gauges & ring gauges

Ring gages used to check external thread, plug gages used to check internal thread.

NPT thread gauges, the full name is National Pipe Taper thread gauges(full name:American National Standard Taper Pipe Thread gages)

NPT threads used on threaded pipes and pipe fittings, they are tapered for sealing, no need any thread sealant.

Thread angle 60°, Taper: 1:16, tooth shape is flat

  • Material:Oil hardened tool steel-Gcr15, high wear resistance.
  • Hardness: 58-62 HRC
  • All gages are brand new
  • gaugestools know the importance of controlling temperature and humidity when testing gages, the temperature will be 20 degree +- 0.5 degree, the humidity will be 45%-65%.
  • Long form calibration certificate from ISO17025 accredited lab can be provided, but it need to be told in advance, and need extra costs.
  • We can provide laser marking service on the gauges. For example, clents’ Logo.
  • Delivery time: 3-5 days.We will send goods by express, Fedex, DHL or UPS. A tracking number will be sent to clients once shipped.
  • all these gauges are fixed limit gauges, inspecting thread on a pass/ fail basis, not checking detailed size of thread.

We have below sizes NPT thread gauges in stock

1/8″-27 NPT 1/4″-18 NPT 3/8″-18 NPT 1/2″-14 NPT
3/4″-14 NPT 1″-11.5 NPT 1 1/4″-11.5 NPT 1 1/2″-11.5 NPT
2″-11.5 NPT 2 1/2″-8 NPT 3″-8 NPT 3 1/2″-8 NPT
4″-8 NPT 5″-8 NPT 6″-8 NPT

NPT thread

NPT thread

H=0.866 025 P ;  h=0.8 P;  f=0.033 P ; P=25.4/n

Taper: 1:16

The taper rate for all NPT threads is 1 inch of diameter in 16 inches of length (3⁄4 inch per foot or 62.5 millimeters per meter) measured by the change of diameter (of the pipe thread) over distance of thread. The angle between the taper and the center axis of the pipe is tan−1( 1⁄32) = 1.7899° = 1° 47′ 24″.

NPT thread gages standard: ANSI/ASME B1.20.1

We know the reliable accuracy is essential,By continuously improving the effectiveness of our process and providing on time 100%-okey products to customers, we will strive to ensure customer satisfaction.

“customer satisfaction” is our pursuit forever.

Accepted payment way: T/T , Paypal or Credit card

Welcome new and old clients come to talk business with us!

How to order:

  • Specify diameter, for example, 1″
  • Specify TPI, for example, TPI 11.5
  • Specify thread form, for example, NPT
  • Specify ring gage or plug gage, ring gage for checking external thread, plug gauge for checking internal thread.
  • Specify quantity
  • After receiving above information, we will make an invoice and send money request, then clients can pay it.

Quality Policy:

At gaugestools, we strive to offer clients quality metric thread ring gages and plug gauges with competitive price and quick shipment. We not only strive to meet clients’ expectations, but also exceed clients’ expectations by continual improvements .

Return Policy:

We will exchange or refund in one week if clients found any products not quality enough or meet clients’ expectations. After receiving our products, once clients have anywhere not satisfied, please contact us at once, clients can send us Email, or contact us with livechat,  we will deal with clients’ problems in quick time, we are committed to providing 100% customer satisfaction.


NPT thread gauge video