Whether you are tapping a thread or drilling a hole, you can find the correct thread size and tap drill you need to use here. We stock a massive range of taps and drills for your next job.
Metric Course Thread Drilling Chart
| Thread Size | Tap Drill (mm) | Thread Size | Tap Drill (mm) | Thread Size | Tap Drill (mm) | Thread Size | Tap Drill (mm) |
|
M1 x 0.25 |
0.75 |
M3.5 x 0.6 |
2.90 |
M12 x 1.75 |
10.20 |
M36 x 4 |
32.00 |
|
M1.1 x 0.25 |
0.85 |
M4 x 0.7 |
3.30 |
M14 x 2 |
12.00 |
M39 x 4 |
35.00 |
|
M1.2 x 0.25 |
0.95 |
M4.5 x 0.75 |
3.70 |
M16 x 2 |
14.00 |
M42 x 4.5 |
37.50 |
|
M1.4 x 0.3 |
1.10 |
M5 x 0.8 |
4.20 |
M18 x 2.5 |
15.50 |
M45 x 4.5 |
40.50 |
|
M1.6 x 0.35 |
1.25 |
M6 x 1 |
5.00 |
M20 x 2.5 |
17.50 |
M48 x 5 |
43.00 |
|
M1.8 x 0.35 |
1.45 |
M7 x 1 |
6.00 |
M22 x 2.5 |
19.50 |
M52 x 5 |
47.00 |
|
M2 x 0.4 |
1.60 |
M8 x 1.25 |
6.80 |
M24 x 3 |
21.00 |
M56 x 5.5 |
50.50 |
|
M2.2 x 0.45 |
1.75 |
M9 x 1.25 |
7.80 |
M27 x 3 |
24.00 |
M60 x 5.5 |
54.50 |
|
M2.5 x 0.45 |
2.05 |
M10 x 1.5 |
8.50 |
M30 x 3.5 |
26.50 |
M64 x 6 |
58.00 |
|
M3 x 0.5 |
2.50 |
M11 x 1.5 |
9.50 |
M33 x 3.5 |
29.50 |
M68 x 6 |
62.00 |
Metric Fine Thread Drilling Chart
| Thread Size | Tap Drill (mm) | Thread Size | Tap Drill (mm) | Thread Size | Tap Drill (mm) | Thread Size | Tap Drill (mm) |
|
M4 x 0.35 |
3.60 |
M10 x 0.75 |
9.25 |
M16 x 1 |
15.0 |
M24 x 1.5 |
22.5 |
|
M4 x 0.5 |
3.50 |
M10 x 1 |
9.0 |
M16 x 1.5 |
15.0 |
M24 x 2 |
22.0 |
|
M5 x 0.5 |
4.50 |
M10 x 1.25 |
8.8 |
M18 x 1 |
17.0 |
M26 x 1.5 |
24.5 |
|
M6 x .5 |
5.50 |
M11 x 1 |
10.0 |
M18 x 2 |
16.0 |
M27 x 1.5 |
25.5 |
|
M6 x .75 |
5.25 |
M12 x .75 |
11.25 |
M20 x 1 |
19.0 |
M27 x 2 |
25.0 |
|
M7 x .75 |
6.25 |
M12 x 1 |
11.0 |
M20 x 1.5 |
18.5 |
M28 x 1.5 |
26.5 |
|
M8 x .5 |
7.00 |
M12 x 1.5 |
10.5 |
M20 x 2 |
18.0 |
M30 x 1.5 |
28.5 |
|
M8 x .75 |
7.25 |
M14 x 1 |
13.0 |
M22 x 1 |
21.0 |
M30 x 2 |
28.0 |
|
M8 x 1 |
7.50 |
M14 x 1.25 |
12.8 |
M22 x 1.5 |
20.5 |
M33 x 2 |
31.0 |
|
M9 x 1 |
8.00 |
M14 x 1.5 |
12.5 |
M22 x 2 |
20.0 |
M36 x 3 |
33.0 |
-
High Speed Ground Thread 8mm 1.00 Taper Tap
$28.00Add to cartView Product -
High Speed Ground Thread 10mm 1.00 Taper Tap
$36.00Add to cartView Product -
High Speed Ground Thread 10mm 1.25 Taper Tap
$36.00Add to cartView Product -
High Speed Ground Thread 12mm 1.25 Taper Tap
$40.00Add to cartView Product
Imperial
UNC
Unified National Coarse
| Tap Size | Drill Size |
| 1/4-20NC | #8 |
| 5/16-18NC | F |
| 3/8-16NC | 5/16 |
| 7/16-14NC | U |
| 1/2-13NC | 27/64 |
| 9/16-12NC | 31/64 |
| 5/8-11NC | 14mm |
| 3/4-10NC | 21/32 |
| 7/8-9NC | 49/64 |
| 1-8NC | 7/8 |
| 1 1/8-7NC | 63/64 |
| 1 1/4-7NC | 1-7/64 |
| 1 3/8-6NC | 1-3/16 |
| 1 1/2-6NC | 1-11/32 |
UNF
Unified National Fine
|
NS
|
NPT
National Pipe Taper 1:16
| Tap Size | Drill Size |
| 1/8-27NPT | R |
| 1/4-18NPT | 7/16 |
| 3/8-18NPT | 15mm |
| 1/2-14NPT | 23/32 |
| 3/4-14NPT | 59/64 |
| 1 x11-1/2NPT | 1-5/32 |
| 1-1/4×11-1/2NPT | 1-1/2 |
| 1-1/2×11-1/2NPT | 1-47/64 |
| 2x 11-1/2NPT | 2-7/32 |
BSW
British Standard Whitworth
| Tap Size | TPI | Tapping Drill Diameter |
| 1/16″ | 60 | 1.15 |
| 3/32″ | 48 | 1.9 |
| 1/8″ | 40 | 2.5 |
| 5/32″ | 32 | 3.2 |
| 3/16″ | 24 | 3.7 |
| 7/32″ | 24 | 4.5 |
| 1/4″ | 20 | 5.1 |
| 5/16″ | 18 | 6.5 |
| 3/8″ | 16 | 7.9 |
| 7/16″ | 14 | 9.2 |
| 1/2″ | 12 | 10.4 |
| 5/8″ | 11 | 13.4 |
| 3/4″ | 10 | 16.25 |
| 7/8″ | 9 | 19.25 |
| 1″ | 8 | 22 |
| 1-1/8″ | 7 | 24.5 |
| 1-1/4″ | 7 | 27.25 |
| 1-3/8″ | 6 | 30.25 |
| 1-1/2″ | 6 | 33.5 |
| 1-5/8″ | 5 | 35.5 |
| 1-3/4″ | 5 | 38.5 |
| 1-7/8″ | 4 1/2 | 41.25 |
| 2″ | 4 1/2 | 44.5 |
| 2-1/4″ | 4 | 50 |
| 2-1/2″ | 4 | 56 |
| 2-3/4″ | 3 1/2 | 61.5 |
| 3″ | 3 1/2 | 68 |
| 3-1/4″ | 3 1/4 | 73.75 |
| 3-1/2″ | 3 1/4 | 80 |
| 3-3/4″ | 3 | 85.5 |
| 4″ | 3 | 92 |
| 4-1/4″ | 2 7/8 | 98 |
| 4-1/2″ | 2 7/8 | 104.2 |
| 4-3/4″ | 2 3/4 | 110 |
| 5″ | 2 3/4 | 116.5 |
| 5-1/4″ | 2 5/8 | 122.5 |
| 5-1/2″ | 2 5/8 | 128.5 |
| 5-3/4″ | 2 1/2 | 134.5 |
| 6″ | 2 1/2 | 141 |
BSF
British Standard Fine
| Tap Size | TPI | Tapping Drill Diameter |
| 3/16″ | 32 | 4 |
| 7/32″ | 28 | 4.6 |
| 1/4″ | 26 | 5.3 |
| 9/32″ | 26 | 6.1 |
| 5/16″ | 22 | 6.8 |
| 3/8″ | 20 | 8.3 |
| 7/16″ | 18 | 9.7 |
| 1/2″ | 16 | 11.1 |
| 9/16″ | 16 | 12.7 |
| 5/8″ | 14 | 14 |
| 11/16″ | 14 | 15.5 |
| 3/4″ | 12 | 16.75 |
| 13/16″ | 12 | 18.25 |
| 7/8″ | 11 | 19.75 |
| 1″ | 10 | 22.75 |
| 1-1/8″ | 9 | 26.5 |
| 1-1/4″ | 9 | 28.75 |
| 1-3/8″ | 8 | 31.5 |
| 1-1/2″ | 8 | 34.5 |
| 1-5/8″ | 8 | 38 |
| 1-3/4″ | 7 | 40.5 |
| 2″ | 7 | 47 |
| 2-1/4″ | 6 | 53 |
| 2-1/2″ | 6 | 59 |
| 2-3/4″ | 6 | n/a |
| 3″ | 5 | n/a |
| 3-1/4″ | 5 | n/a |
| 3-1/2″ | 4 1/2 | n/a |
| 3-3/4″ | 4 1/2 | n/a |
| 4″ | 4 1/2 | n/a |
| 4-1/4″ | 4 | n/a |
UNEF
Unified National Form
| Tap Size | TPI | Tapping Drill mm |
| 1/4 | 32 | 5.6 |
| 5/16 | 32 | 7.2 |
| 3/8 | 32 | 8.8 |
| 1/2 | 28 | 11.8 |
| 5/8 | 24 | 14.75 |
| 3/4 | 20 | 18 |
| 1 | 20 | 24.2 |
BSB
British Standard Brass
| Tap Size | TPI | Tapping Drill mm |
| 1/4 | 26 | 5.2 |
| 5/16 | 26 | 6.8 |
| 3/8 | 26 | 8.4 |
| 7/16 | 26 | 10 |
| 1/2 | 26 | 11.6 |
| 9/16 | 26 | 13.2 |
| 5/8 | 26 | 14.8 |
| 3/4 | 26 | 18 |
| 7/8 | 26 | 20.8 |
| 1 | 26 | 24.3 |
