ASME B18.31.2 Tap End Studs
Dimensions for Tap End Studs to ASME B18.31.2 Standard
| Nominal Size Thread Diameter, D, Inch. |
Tap End Full Thread Length, BM | Umax = 2P | Minimum Nut End Full Thread Length, Bmin | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Nominal | Min. | Max. | UNC & NC-5 Thread | UNF Thread | 8UN Thread | L ≤ 10 | 10 < L ≤ 16 | L > 16 | |
| 1/4 | 0.375 | 0.350 | 0.400 | 0.100 | 0.071 | ... | 0.750 | 1.000 | 1.500 |
| 5/16 | 0.469 | 0.440 | 0.498 | 0.111 | 0.083 | -- | 0.875 | 1.125 | 1.625 |
| 3/8 | 0.563 | 0.532 | 0.594 | 0.125 | 0.083 | -- | 1.000 | 1.250 | 1.750 |
| 7/16 | 0.656 | 0.620 | 0.692 | 0.143 | 0.100 | -- | 1.125 | 1.375 | 1.875 |
| 1/2 | 0.750 | 0.708 | 0.792 | 0.154 | 0.100 | -- | 1.250 | 1.500 | 2.000 |
| 9/16 | 0.844 | 0.802 | 0.896 | 0.167 | 0.111 | -- | 1.375 | 1.625 | 2.125 |
| 5/8 | 0.938 | 0.892 | 0.983 | 0.182 | 0.111 | -- | 1.500 | 1.750 | 2.250 |
| 3/4 | 1.1.25 | 1.075 | 1.175 | 0.200 | 0.125 | -- | 1.750 | 2.000 | 2.500 |
| 7/8 | 1.313 | 1.258 | 1.368 | 0.222 | 0.143 | -- | 2.000 | 2.250 | 2.750 |
| 1 | 1.500 | 1.438 | 1.562 | 0.250 | 0.167 | -- | 2.250 | 2.500 | 3.000 |
| 1 1/8 | 1.688 | 1.625 | 1.750 | 0.286 | 0.167 | 0.250 | 2.500 | 2.750 | 3.250 |
| 1 1/4 | 1.875 | 1.813 | 1.938 | 0.286 | 0.167 | 0.250 | 2.750 | 3.000 | 3.500 |
| 1 3/8 | 2.063 | 2.000 | 2.125 | 0.333 | 0.167 | 0.250 | 3.000 | 3.250 | 3.750 |
| 1 1/2 | 2.250 | 2.188 | 2.313 | 0.333 | 0.167 | 0.250 | 3.250 | 3.500 | 4.000 |
| 1 5/8 | 2.438 | 2.375 | 2.500 | -- | -- | 0.250 | 3.500 | 3.750 | 4.250 |
| 1 3/4 | 2.625 | 2.563 | 2.688 | 0.400 | -- | 0.250 | 3.750 | 4.000 | 4.500 |
| 1 7/8 | 2.813 | 2.750 | 2.875 | -- | -- | 0.250 | 4.000 | 4.250 | 4.750 |
| 2 | 3.000 | 2.925 | 3.075 | 0.444 | -- | 0.250 | 4.250 | 4.500 | 5.000 |
| 2 1/4 | 3.375 | 3.300 | 3.450 | 0.444 | -- | 0.250 | 4.750 | 5.000 | 5.500 |
| 2 1/2 | 3.750 | 3.675 | 3.825 | 0.500 | -- | 0.250 | 5.250 | 5.500 | 6.000 |
| 2 3/4 | 4.125 | 4.050 | 4.200 | 0.500 | -- | 0.250 | 5.750 | 6.000 | 6.500 |
| 3 | 4.500 | 4.425 | 4.575 | 0.500 | -- | 0.250 | -- | 6.500 | 7.000 |
| 3 1/4 | 4.875 | 4.775 | 4.975 | 0.500 | -- | 0.250 | -- | 7.000 | 7.500 |
| 3 1/2 | 5.250 | 5.150 | 5.350 | 0.500 | -- | 0.250 | -- | 7.500 | 8.000 |
| 3 3/4 | 5.625 | 5.525 | 5.725 | 0.500 | -- | 0.250 | -- | 8.000 | 8.500 |
| 4 | 6.000 | 5.900 | 6.100 | 0.500 | -- | 0.250 | -- | 8.500 | 9.000 |
General Notes :
B = full nut end thread length
Bm = tap end thread length (full threads)
LT = overall length (nominal length)
S = Standoff (when installed) = LT - BM
U = length to first full form thread.
Notes :
- UNC Threads are standards for low strength materials, but UNF threads are usually available on special order.