What is the thread pitch of 1/8 NPT?

What is the thread pitch of 1/8 NPT?

NPT and NPTF pipe threads – dimensions according ANSI/ASME B1. 20.1/3

NPT – American Standard Pipe Thread Taper 1)
Pipe Size (inches) TPI Nominal Outside Diameter Pipe OD (inches)
1/16″ 27 0.313
1/8″ 27 0.405
1/4″ 18 0.540

What size drill bit do I use for a 1/8 NPT tap?

NPT Tap Drill Chart

Tap Size Drill Size Tap and Drill Set
1/8″ NPT Tap “R” Drill Bit 1/8″ NPT Tap and Drill Set
1/4″ NPT Tap 7/16″ Drill Bit 1/4″ NPT Tap and Drill Set
3/8″ NPT Tap 37/64″ Drill Bit 3/8″ NPT Tap and Drill Set
1/2″ NPT Tap 23/32″ Drill Bit 1/2″ NPT Tap and Drill Set

How do you calculate tap drill size?

How to Calculate Tap Drill Size. Apply the numbers to the formula using an 84 percent thread depth. The formula would be: Dh = 0.252 — 0.0130 (84/20) = 0.0130 (4.2) = 0.252 — 0.0546 = 0.1974 inches. Find the nearest drill bit size in 1/16ths of an inch. Multiply 0.1974 times 16 and the answer is 3.15.

What size drill bit for 1/8 NPT tap?

If you must drill, an “R” (letter size) drill is more commonly used for a 1/8 NPT tap. 5/16 will work, but will be tight. What size drill bit should I use? How to Choose Drill Bits by Size Use a bit 1/64″ smaller than the target hole size for softwoods.

How to measure NPT fittings?

National Pipe Thread Tapered (NPT) is one of the U.S. standards for tapered threads used to join pipes and fittings. The taper rate for all NPT threads is 1⁄16 (¾” per foot) measured by the change of diameter (of the pipe thread) over distance.

What is the formula for tap drill size?

Measure the overall diameter of the tap with the micrometer. In this particular instance,we want a drill bit for a ¼ – 20 tap.

  • Use the following formula for finding the correct drill bit size: Dh = Dbm — 0.0130 (percentage of the full thread desired/Ni).
  • Apply the numbers to the formula using an 84 percent thread depth.
  • author

    Back to Top