Pipe Tap Drill Chart

February 25, 2024 Post a Comment

Pipe tap drill chart

A 37/64″ drill bit is needed for a 3/8″ NPT tap.

How do I know what size drill to tap?

Tap-drill diameter equals nominal diameter minus thread pitch. I quickly calculate proper tap-drill diameters using this simple formula. Tap-drill diameter equals nominal diameter minus thread pitch. For example, drill size for a 3/8-16 thread is 0.375 0.0625 (pitch) = 0.312 in.

What is pipe tap size?

Commonly used sizes are 1/⁄ 8 , 1/4 , 3/⁄ 8 , 1/2 , 3/4 , 1, 1 1/⁄ 4 , 1 1/2 , and 2 inch, appearing on pipes and fittings by most U.S. suppliers.

How much tap length should I use when tapping pipe?

Most standard pipe taps have a maximum chamfer length that ranges between 3 and 4 threads. Therefore, the tapping depth should be the approx. 5 threads for the “hand tight”, 3 threads for “wrench tight”, and 4 threads for the chamfer, or approx.

What size drill do I need for 1/8 inch pipe tap?

If you have a 1/8'' NPT pipe tap, the R type is the appropriate drill bit to use with this tap. If the pipe tap is tapered, the ideal drill size is 21/64mm in fraction form or 0.339''. For non-tapered or straight pipe tap, use a drill size of 11/32mm or 0.344''.

What size drill bit do I need to tap a 3/8 16 hole?

What Size of Drill Bit Do I Need for a 3/8-16 Tap? A 3/8-16 tap should be used with a drill bit size of 5/16-inch.

What size hole do I drill for a 1/2 inch pipe tap?

Tap Size	Drill Size	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
3/4" NPT Tap	59/64" Drill Bit	3/4" NPT Tap and Drill Set
1" NPT Tap	1-5/32" Drill Bit	1" NPT Tap and Drill Set

Do you drill a hole the same size as the tap?

Step 1: Drill the Hole Your hole will be smaller than the diameter of the bolt, because the threads tapped will increase the diameter. The chart above matches tap, or bolt, sizes up with their corresponding drill bit size.

What size drill bit do I need for a 1 inch pipe tap?

Tap size	Threads per inch	Drill size w/ taper pipe reamer
1	11.5	1 1/8
1 1/4	11.5	1 15/32
1 1/2	11.5	1 23/32
2	11.5	2 3/16

What are the 3 types of taps?

So what are the types of taps? There are 3 main taps you should be familiar with and they are: Taper, Plug, and Bottoming tap.

What does a 1/4 20 tap mean?

Thus, a tap or die marked 1/4-20 NC cuts threads for a 1/4-inch-diameter screw or bolt with 20 coarse threads per inch. Taps and dies with diameters less than 1/4-inch are numbered according to the wire gauge sizes of machine screws.

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

A #7 drill bit with a diameter of 13/64″ (0.203′′) is the best choice for 1/4′′ 20 UNC tap threads. Tapping threads is a fairly straightforward process. It's difficult to screw the bolt in if the hole is too small because the tapping will stick out into the center.

What is the formula for tapping?

In/Min = RPM divided by # of Threads / in.

How is tapping depth calculated?

Since the width of the thread and circumference of the bolt are known, we can calculate the number of threads. Now we know the pitch of the threads and the number of threads, so we can calculate the threaded depth. As it turns out, this can usually be simplified to Threaded Depth = 1.5 x Diameter.

What is the best rpm for tapping?

For best results, the speed of the spindle should be between 150 and 250 rpm. Get a tap guide. The hole is now ready to tap.

What is the diameter of 1/8 inch pipe?

SCH 40 Pipe 1/8" (0.269ID) X 0.405 OD.

What is the diameter of 1/8 pipe thread?

Nominal Pipe Size	Outside Diameter of Pipe	Threads per Inch
1/16	0.313	27
1/8	0.405	27
1/4	0.540	18
3/8	0.675	18

What size is a 1/4 tap?

To Tap This Size Screw Or Bolt:	Use This Drill Bit:	(Closest Fractional:)
1/4-28 NF	#3	7/32"
1/4-32 NEF	7/32"	7/32"
1/4-40 NS	#1	-
7mm-1.00mm	6.1mm	15/64"

What size drill do I use for a 3/16 tap?

Tap Size	TPI	Tapping Drill Diameter
3/16″	24	3.7
7/32″	24	4.5
1/4″	20	5.1
5/16″	18	6.5

What is the tap drill for a 3/8 16 bolt?

Most drill charts recommend a 5/16 drill for a 3/8-16 bolt. Cutting holes that are smaller will leave more material for the tap to cut out, risking tap breakage.