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1-11.5 NPT thread: 33.4 mm × 11.5 TPI

Threads › 1-11.5 NPT

1-11.5 NPT is an NPT taper thread: 33.4 mm pipe OD, 11.5 TPI (2.209 mm pitch), 60° form. Tap drill 29.4 mm. Taper thread: the Ø changes along the length, measure near the start.

StandardNPT taper
Pipe OD33.401 mm (1.315″)
Pitch11.5 TPI (2.209 mm)
Thread angle60°
Tap drill29.4 mm

Open 1-11.5 NPT in BenchsmithAdd to order list

Measure it

Bolt: Measure across the crests of the bolt with the caliper jaws. Worn bolts read 0.1 to 0.3 under.

Nut or tapped hole: Measure across the tops of the threads inside the nut or hole with the inside jaws. That is the minor Ø. Worn or oversize holes read a little over.

Close in size, won't mate

One size up or down

Got a bolt and no idea what it is? Measure the outside Ø and type it into Benchsmith → Find → Thread.