What Tap do I need for 1/4 NPT?

What Tap do I need for 1/4 NPT?

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

What drill is used to tap a 1 4 18 NPT hole?


NPT Size Tap Drill Size (in.) (Decimal) (in.)
1/16 – 27 “C” (0.242)
1/8 – 27 “Q” (0.332)
1/4 – 18 7/16 (0.438)
3/8 – 18 9/16 (0.562)

What size hole do you drill for a 1/4 NPT tap?

If you intend to use the drill-only method to prepare the starter hole for a 1/4-18 NPT tap, use a 7/16 inch drill bit. If you choose to use the drill-and-reamer methods, use a 27/64 inch bit, followed by a 1/4-18 tapered pipe reamer. In either case, you should resist the temptation to use old drill bits.

Can you tap NPT?

Selecting taps for cutting taper pipe threads requires some investigation to ensure two important requirements are met. The use of an NPTF marked tap for NPT applications is appropriate, however NPT taps cannot be used for dryseal (NPTF). When visually comparing these two styles in the same size they look identical.

What is the drill size for a 1/4 20 tap?

To Tap This Size Screw Or Bolt: Use This Drill Bit: (Closest Fractional:)
14-20 NS #10
1/4-20 NC #7 13/64″
14-24 NS #7
6mm-1.00mm 5.2mm

What size drill bit do you use for a 1/4 tap?

What Size Drill Bit for 1/4″ 20 Tap?

Screw Size Drill Bit Drill Bit Size
1/4″ 20 Tap #7 13/64″
1/4″ 28 Tap #3 7/32″

What does NPT stand for?

National Pipe Thread
NPT: National Pipe Thread (tapered) is a U.S. standard for tapered threads.

What size drill bit do you use for 1/4-20 tap?

Are NPT taps tapered?

NPT tap threads can be either tapered or straight, depending on the job at hand. The taper on NPT pipe taps means a seal is tightly formed when correctly torqued.

What does a 1/4-20 tap mean?

Example: 1/4 – 20NC The 1/4 represents the diameter of the thread in inches. The 20 represents the number of threads per inch or TPI. Standard taps are either standard coarse series threads NC (1/4-20), fine series threads NF (1/4-28) or extra fine series NEF (1/4-32).

What number is a 1/4 inch drill bit?

Drill Bit Hole Diameters
Metric Size Fractional Size
5 mm .1968 7/32
6 mm .2362 15/64
7 mm .2756 1/4

How do you measure NPT fittings?

How to measure NPT fittings. Align the 2.5 cm (1 inch) mark of a tape measure with one inside edge of the NPT fitting. Pull the tape measure across the opening of the fitting. Note the measurement to the other side of its other inside edge. Align and measure the distance across the narrowest part of the threads, if measuring a threaded NPT fitting.

What size drill do you use for tap?

Drill Bit Sizes (Metric) The drill size chart contains tools up to 1.5 inches in diameter,but larger tools are also commonly used.

  • Drill Bit Sizes (English)
  • Tap Sizes (Metric) For each thread count,the equivalent thread pitch is provided and for metric taps,the approximate thread count is shown based on the pitch.
  • Tap Sizes (English)
  • What is National Pipe Thread?

    American National Standard Pipe Thread standards, often called national pipe thread standards for short, are U.S. national technical standards for screw threads used on threaded pipes and pipe fittings. They include both tapered and straight thread series for various purposes including rigidity, pressure-tight sealing, or both.

    What is a NPT fitting?

    NPT stands for National Pipe Taper, and is the most common U.S. standard for pipe fittings. NPT fittings are measured on the internal diameter of the fitting.

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