Threads
Jump to navigation
Jump to search
Standard Screw Threads and Tap Drill Sizes
No. | Thread | Tap Drill | Clear Drill |
---|---|---|---|
0 | 80 | 56 | 52 |
1 | 72 | 53 | 48 |
2 | 56 | 49 | 43 |
3 | 48 | 47 | 39 |
4 | 40 | 44 | 32 |
5 | 40 | 39 | 30 |
6 | 32 | 36 | 28 |
8 | 36 | 29 | 19 |
10 | 32 | 21 | 11 |
12 | 24 | 16 | 2 |
Size | Thread | Tap Drill |
---|---|---|
1/4 | 28 | 3 |
5/16 | 24 | I |
3/8 | 24 | Q |
7/16 | 20 | 25/64 |
1/2 | 20 | 29/64 |
Size | Thread | Tap Drill |
---|---|---|
1/4 | 20 | 7 |
5/16 | 18 | F |
3/8 | 16 | 5/16 |
7/16 | 14 | U |
1/2 | 13 | 27/64 |
9/16 | 12 | 31/64 |
5/8 | 11 | 17/32 |
Machine Screw Diameters
The Miniature Locomotive, July-August 1954
Machine screws are numbered as distinct from Cap Screws, Bolts, etc, and range usually from #0 to #12. A convenient method of finding the exact diameter if a table is not handy is as follows:
- Multiply the number of 13 and add sixty thousandths. The answer will be thousandths.
Examples:
- #0 -- 0 multiplied by 13 equals 0, plus 0.060 equals 0.060
- #3 -- 3 multiplied by 13 equals 39, plus 0.060 equals 0.099
- #5 -- 5 multiplied by 13 equals 65, plus 0.060 equals 0.125
- #10 -- 10 multiplied by 13 equals 0.130, plus 0.060 equals 0.190