Table 3. Recommended Hole Size Limits Before Tapping Unified Threads Table 3. (Continued) Recommended Hole Size Limits Before Tapping Unified Threads
Classes 1B and 2B
Class 3B
Length of Engagement ( D = Nominal Size of Thread)
Thread Size
Above 2 ∕ 3 D to 1 1 ∕ 2 D
Above 1 1 ∕ 2 D to 3 D
Above 2 ∕ 3 D to 1 1 ∕ 2 D
Above 1 1 ∕ 2 D to 3 D
Above 1 ∕ 3 D to 2 ∕ 3 D
Above 1 ∕ 3 D to 2 ∕ 3 D
To and Including 1 ∕ 3 D
To and Including 1 ∕ 3 D
Recommended Hole Size Limits
Min a 1.120 1.127 1.095 1.115 1.160 1.182 1.190 1.196 1.222 1.245 1.252 1.195 1.240 1.285 1.307 1.315 1.347 1.370 1.377 1.320 1.365 1.410 1.432 1.440 1.446 1.495 1.502
Max b 1.134 1.140 1.123 1.140 1.178 1.196 1.203 1.207 1.240 1.259 1.265 1.225 1.265 1.303 1.321 1.328 1.365 1.384 1.390 1.350 1.390 1.428 1.446 1.452 1.457 1.509 1.515
Min a
Max b
Max 1.127 1.134 1.109 1.128 1.169 1.189 1.197 1.202 1.231 1.252 1.259 1.210 1.253 1.294 1.314 1.322 1.354 1.377 1.384 1.335 1.378 1.419 1.439 1.446 1.452 1.502 1.509
Min 1.124 1.130 1.102 1.121 1.165 1.186 1.193 1.199 1.227 1.249 1.256 1.203 1.246 1.290 1.311
Max 1.131 1.137 1.116 1.134 1.174 1.193 1.200 1.204 1.236 1.256 1.262 1.221 1.259 1.299 1.318 1.325 1.361 1.381 1.387 1.346 1.384 1.424 1.443 1.450 1.454 1.506 1.512
Min 1.127 1.134 1.109 1.128 1.169 1.189 1.197 1.202 1.231 1.252 1.259 1.210 1.253 1.294 1.314 1.322 1.354 1.377 1.384 1.335 1.378 1.419 1.439 1.446 1.452 1.502 1.509
Min 1.131 1.137 1.116 1.134 1.174 1.193 1.200 1.204 1.236 1.256 1.262 1.221 1.259 1.299 1.318 1.325 1.361 1.381 1.387 1.346 1.384 1.424 1.443 1.450 1.454 1.506 1.512
Max 1.138 1.143 1.130 1.146 1.183 1.200 1.206 1.210 1.245 1.263 1.268 1.239 1.271 1.308 1.325 1.331 1.370 1.388 1.393 1.364 1.396 1.433 1.450 1.456 1.460 1.513 1.518
Max
Min
Max
Min
Min
Max
1.1200 1.1241 1.1219 1.1262 1.1240 1.1283 1.1261 1.1304 1.1270 1.1315 1.1294 1.1335 1.1314 1.1355 1.1335 1.1376 1.0950 1.1040 1.0997 1.1083 1.1039 1.1125 1.1082 1.1168 1.1150 1.1222 1.1184 1.1259 1.1222 1.1297 1.1260 1.1335 1.1600 1.1648 1.1623 1.1673 1.1648 1.1698 1.1673 1.1723 1.1820 1.1866 1.1844 1.1887 1.1865 1.1908 1.1886 1.1929 1.1900 1.1940 1.1919 1.1960 1.1939 1.1980 1.1960 1.2001 1.1960 1.1998 1.1977 1.2017 1.1997 1.2037 1.2016 1.2056 1.2220 1.2273 1.2248 1.2298 1.2273 1.2323 1.2298 1.2348 1.2450 1.2491 1.2469 1.2512 1.2490 1.2533 1.2511 1.2554 1.2520 1.2565 1.2544 1.2585 1.2564 1.2605 1.2585 1.2626 1.1950 1.2046 1.1996 1.2096 1.2046 1.2146 1.2096 1.2196 1.2400 1.2472 1.2434 1.2509 1.2472 1.2547 1.2510 1.2585 1.2850 1.2898 1.2873 1.2923 1.2898 1.2948 1.2923 1.2973 1.3070 1.3116 1.3094 1.3137 1.3115 1.3158 1.3136 1.3179 1.3150 1.3190 1.3169 1.3210 1.3189 1.3230 1.3210 1.3251 1.3470 1.3523 1.3498 1.3548 1.3523 1.3573 1.3548 1.3598 1.3700 1.3741 1.3719 1.3762 1.3740 1.3783 1.3761 1.3804 1.3770 1.3815 1.3794 1.3835 1.3814 1.3855 1.3835 1.3876 1.3200 1.3296 1.3246 1.3346 1.3296 1.3396 1.3346 1.3446 1.3650 1.3722 1.3684 1.3759 1.3722 1.3797 1.3760 1.3835 1.4100 1.4148 1.4123 1.4173 1.4148 1.4198 1.4173 1.4223 1.4320 1.4366 1.4344 1.4387 1.4365 1.4408 1.4386 1.4429 1.4400 1.4440 1.4419 1.4460 1.4439 1.4480 1.4460 1.4501 1.4460 1.4498 1.4477 1.4517 1.4497 1.4537 1.4516 1.4556 1.4950 1.4991 1.4969 1.5012 1.4990 1.5033 1.5011 1.5054 1.5020 1.5065 1.5044 1.5085 1.5064 1.5105 1.5085 1.5126
1 3 ∕ 16 -16 1 3 ∕ 16 -18 1 1 ∕ 4 -7 1 1 ∕ 4 -8 1 1 ∕ 4 -12 1 1 ∕ 4 -16 1 1 ∕ 4 -18 1 1 ∕ 4 -20 1 5 ∕ 16 -12 1 5 ∕ 16 -16 1 5 ∕ 16 -18 1 3 ∕ 8 -6 1 3 ∕ 8 -8 1 3 ∕ 8 -12 1 3 ∕ 8 -16 1 3 ∕ 8 -18 1 7 ∕ 16 -12 1 7 ∕ 16 -16 1 7 ∕ 16 -18 1 1 ∕ 2 -6 1 1 ∕ 2 -8 1 1 ∕ 2 -12 1 1 ∕ 2 -16 1 1 ∕ 2 -18 1 1 ∕ 2 -20 1 9 ∕ 16 -16 1 9 ∕ 16 -18
1.318 1.350 1.374 1.380 1.328 1.371 1.4155 1.436 1.443 1.449 1.499 1.505
Made with FlippingBook - Share PDF online