UNC and UNF Threads [FuddyMuckers]

This page is read only. You can view the source, but not change it. Ask your administrator if you think this is wrong.
====== UNC and UNF Threads ======

**Sizes, drills & taps - applies to nuts, bolts, screws.**

**UNC = Unified National Coarse Threads**

**UNF = Unified National Fine Thread**

===== UNC threads according ANSI B1.1: =====

^ Name / description (in) ^ Threads per inch (tpi) ^ Major Diameter ^^ Tap Drill Size (mm) ^ Pitch (mm) ^
^ ::: ^ ::: ^ (in) ^ (mm) ^ ::: ^ ::: ^
|   #1 - 64  |   64  |  0.073  |  1.854  |  1.50  |  0.397  |
|  #2 - 56  |  56  |  0.086  |  2.184  |  1.80  |  0.453  |
|  #3 - 48  |  48  |  0.099  |  2.515  |  2.10  |  0.529  |
|  #4 - 40  |  40  |  0.112  |  2.845  |  2.35  |  0.635  |
|  #5 - 40  |  40  |  0.125  |  3.175  |  2.65  |  0.635  |
|  #6 - 32  |  32  |  0.138  |  3.505  |  2.85  |  0.794  |
|  #8 - 32  |  32  |  0.164  |  4.166  |  3.50  |  0.794  |
|  #10 - 24  |  24  |  0.190  |  4.826  |  4.00  |  1.058  |
|  #12 - 24  |  24  |  0.216  |  5.486  |  4.65  |  1.058  |
|  1/4" - 20  |  20  |  0.250  |  6.350  |  5.35  |  1.270  |
|  5/16" - 18  |  18  |  0.313  |  7.938  |  6.80  |  1.411  |
|  3/8" - 16  |  16  |  0.375  |  9.525  |  8.25  |  1.587  |
|  7/16" - 14  |  14  |  0.438  |  11.112  |  9.65  |  1.814  |
|  1/2" - 13  |  13  |  0.500  |  12.700  |  11.15  |  1.954  |
|  9/16" - 12  |  12  |  0.563  |  14.288  |  12.60  |  2.117  |
|  5/8" - 11  |  11  |  0.625  |  15.875  |  14.05  |  2.309  |
|  3/4" - 10  |  10  |  0.750  |  19.050  |  17.00  |  2.540  |
|  7/8" - 9  |  9  |  0.875  |  22.225  |  20.00  |  2.822  |
|  1" - 8  |  8  |  1.000  |  25.400  |  22.85  |  3.175  |
|  1 1/8" - 7  |  7  |  1.125  |  28.575  |  25.65  |  3.628  |
|  1 1/4" - 7  |  7  |  1.250  |  31.750  |  28.85  |  3.628  |
|  1 3/8" - 6  |  6  |  1.375  |  34.925  |  31.55  |  4.233  |
|  1 1/2" - 6  |  6  |  1.500  |  38.100  |  34.70  |  4.233  |
|  1 3/4" - 5  |  5  |  1.750  |  44.450  |  40.40  |  5.080  |
|  2" - 4 1/2  |  4 1/2  |  2.000  |  50.800  |  46.30  |  5.644  |
|  2 1/4" - 4 1/2  |  4 1/2  |  2.250  |  57.150  |  52.65  |  5.644  |
|  2 1/2" - 4  |  4  |  2.500  |  63.500  |  58.50  |  6.350  |
|  2 3/4" - 4  |  4  |  2.750  |  69.850  |  64.75  |  6.350  |
|  3" - 4  |  4  |  3.000  |  76.200  |  71.10  |  6.350  |
|  3 1/4" - 4  |  4  |  3.250  |  82.550  |  77.45  |  6.350  |
|  3 1/2" - 4  |  4  |  3.500  |  88.900  |  83.80  |  6.350  |
|  3 3/4" - 4  |  4  |  3.750  |  95.250  |  90.15  |  6.350  |
|  4" - 4  |  4  |  4.000  |  101.600  |  96.50  |  6.350  |

===== UNF threads ANSI B1.1 =====

^ Name / description (in) ^ Threads per inch (tpi) ^ Major Diameter ^^ Tap Drill Size (mm) ^ Pitch (mm) ^
^ ::: ^ ::: ^ (in) ^ (mm) ^ ::: ^ ::: ^
|  #0 - 80  |  80  |  0.060  |  1.524  |  1.25  |  0.317  |
|  #1 - 72  |  72  |  0.073  |  1.854  |  1.55  |  0.353  |
|  #2 - 64  |  64  |  0.086  |  2.184  |  1.90  |  0.397  |
|  #3 - 56  |  56  |  0.099  |  2.515  |  2.15  |  0.453  |
|  #4 - 48  |  48  |  0.112  |  2.845  |  2.40  |  0.529  |
|  #5 - 44  |  44  |  0.125  |  3.175  |  2.70  |  0.577  |
|  #6 - 40  |  40  |  0.138  |  3.505  |  2.95  |  0.635  |
|  #8 - 36  |  36  |  0.164  |  4.166  |  3.50  |  0.705  |
|  #10 - 32  |  32  |  0.190  |  4.826  |  4.10  |  0.794  |
|  #12 - 28  |  28  |  0.216  |  5.486  |  4.70  |  0.907  |
|  1/4" - 28  |  28  |  0.250  |  6.350  |  5.50  |  0.907  |
|  5/16" - 24  |  24  |  0.313  |  7.938  |  6.90  |  1.058  |
|  3/8" - 24  |  24  |  0.375  |  9.525  |  8.50  |  1.058  |
|  7/16" - 20  |  20  |  0.438  |  11.112  |  9.90  |  1.270  |
|  1/2" - 20  |  20  |  0.500  |  12.700  |  11.50  |  1.270  |
|  9/16" - 18  |  18  |  0.563  |  14.288  |  12.90  |  1.411  |
|  5/8" - 18  |  18  |  0.625  |  15.875  |  14.50  |  1.411  |
|  3/4" - 16  |  16  |  0.750  |  19.050  |  17.50  |  1.587  |
|  7/8" - 14  |  14  |  0.875  |  22.225  |  20.40  |  1.814  |
|  1" - 12  |  12  |  1.000  |  25.400  |  23.25  |  2.117  |
|  1 1/8" - 12  |  12  |  1.125  |  28.575  |  26.50  |  2.117  |
|  1 1/4" - 12  |  12  |  1.250  |  31.750  |  29.50  |  2.117  |
|  1 3/8" - 12  |  12  |  1.375  |  34.925  |  32.75  |  2.117  |
|  1 1/2" - 12  |  12  |  1.500  |  38.100  |  36.00  |  2.117  |