What size drill bit do I need for a 1/4 NPT tap?
7/16″
NPT Tap Drill Chart
| Tap Size | Drill Size | 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 |
| 3/4″ NPT Tap | 59/64″ Drill Bit | 3/4″ NPT Tap and Drill Set |
What size hole do you drill for a 1/4 inch tap?
One of the most common sizes is a quarter-inch with 20 threads per inch, so you will want to know what size drill bit for 1/4″ 20 tap….What Size Drill Bit for 1/4″ 20 Tap?
| Screw Size | Drill Bit | Drill Bit Size |
|---|---|---|
| 1/4″ 28 Tap | #3 | 7/32″ |
How deep do you tap an NPT thread?
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. 12 threads total.
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 |
What does NS stand for on a tap?
NS means special thread. Pitch Diameter is the basic dimension of a screw, threaded hole, or a tap the diameter of an imaginary cylinder, the surface of which passes through the thread where width of thread and space between threads are identical. This cylinder, of course, would be a cone for tapered taps.
What size hole do I need to drill for a 1/4-20 tap?
For a 1/4-20 bolt, the optimal drill bit size is #7 or 13/64th.
How do you drill 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.
What size is a #4 drill bit?
| To Tap This Size Screw Or Bolt: | Use This Drill Bit: | Decimal Inches |
|---|---|---|
| 6mm-1.00mm | 5.2mm | .2047 |
| 1/4-24 NS | #4 | .2090 |
| 1/4-28 NF | #3 | .2130 |
| 1/4-32 NEF | 7/32″ | .2188 |