Thread Plug Gages
| NOMINAL SIZE | GO BASIC ALL CLASSES ALL SERIES |
UNIFIED PITCH DIAMETERS | ||||
|---|---|---|---|---|---|---|
| NOT GO | X TOL. GO =+ NO GO =– |
X LEAD TOL. |
X ± HALF ANGLE TOL. |
|||
| CL. 2B | CL. 3B | |||||
| #0 - 80 UNF | .0519 | .0542 | .0536 | .0002 | .0002 | 0°30' |
| #1 - 64 UNC | .0629 | .0655 | .0648 | .0002 | .0002 | 0°30' |
| #1 - 72 UNF | .0640 | .0665 | .0659 | .0002 | .0002 | 0°30' |
| #2 - 56 UNC | .0744 | .0772 | .0765 | .0002 | .0002 | 0°30' |
| #2 - 64 UNF | .0759 | .0786 | .0779 | .0002 | .0002 | 0°30' |
| #3 - 48 UNC | .0855 | .0885 | .0877 | .0002 | .0002 | 0°30' |
| #3 - 56 UNF | .0874 | .0902 | .0895 | .0002 | .0002 | 0°30' |
| #4 - 40 UNC | .0958 | .0991 | .0982 | .0002 | .0002 | 0°20' |
| #4 - 48 UNF | .0985 | .1016 | .1008 | .0002 | .0002 | 0°30' |
| #5 - 40 UNC | .1088 | .1121 | .1113 | .0002 | .0002 | 0°20' |
| #5 - 44 UNF | .1102 | .1134 | .1126 | .0002 | .0002 | 0°20' |
| #6 - 32 UNC | .1177 | .1214 | .1204 | .0003 | .0003 | 0°15' |
| #6 - 40 UNF | .1218 | .1252 | .1243 | .0002 | .0002 | 0°20' |
| #8 - 32 UNC | .1437 | .1475 | .1465 | .0003 | .0003 | 0°15' |
| #8 - 36 UNF | .1460 | .1496 | .1487 | .0002 | .0002 | 0°20' |
| #10 - 24 UNC | .1629 | .1672 | .1661 | .0003 | .0003 | 0°15' |
| #10 - 32 UNF | .1697 | .1736 | .1726 | .0003 | .0003 | 0°15' |
| #12 - 24 UNC | .1889 | .1933 | .1922 | .0003 | .0003 | 0°15' |
| #12 - 28 UNF | .1928 | .1970 | .1959 | .0003 | .0003 | 0°15' |
| #12 - 32 UNEF | .1957 | .1998 | .1988 | .0003 | .0003 | 0°15' |
| 1/4 - 20 UNC | .2175 | .2224 | .2211 | .0003 | .0003 | 0°15' |
| 1/4 - 28 UNF | .2268 | .2311 | .2300 | .0003 | .0003 | 0°15' |
| 1/4 - 32 UNEF | .2297 | .2339 | .2328 | .0003 | .0003 | 0°15' |
| 5/16 -18 UNC | .2764 | .2817 | .2803 | .0003 | .0003 | 0°10' |
| 5/16 - 24 UNF | .2854 | .2902 | .2890 | .0003 | .0003 | 0°15' |
| 5/16 - 32 UNEF | .2922 | .2964 | .2953 | .0003 | .0003 | 0°15' |
| 3/8 - 16 UNC | .3344 | .3401 | .3387 | .0003 | .0003 | 0°10' |
| 3/8 - 24 UNF | .3479 | .3528 | .3516 | .0003 | .0003 | 0°15' |
| 3/8 - 32 UNEF | .3547 | .3591 | .3580 | .0003 | .0003 | 0°15' |
| 7/16 - 14 UNC | .3911 | .3972 | .3957 | .0003 | .0003 | 0°10' |
| 7/16 - 20 UNF | .4050 | .4104 | .4091 | .0003 | .0003 | 0°15' |
| 7/16 - 28 UNEF | .4143 | .4189 | .4178 | .0003 | .0003 | 0°15' |
| 1/2 - 13 UNC | .4500 | .4565 | .4548 | .0003 | .0003 | 0°10' |
| 1/2 - 20 UNF | .4675 | .4731 | .4717 | .0003 | .0003 | 0°15' |
| 1/2 - 28 UNEF | .4768 | .4816 | .4804 | .0003 | .0003 | 0°15' |
| 9/16 - 12 UNC | .5084 | .5152 | .5135 | .0003 | .0003 | 0°10' |
| 9/16 - 18 UNF | .5264 | .5323 | .5308 | .0003 | .0003 | 0°10' |
| 9/16 - 24 UNEF | .5354 | .5405 | .5392 | .0003 | .0003 | 0°15' |
| 5/8 - 11 UNC | .5660 | .5732 | .5714 | .0003 | .0003 | 0°10' |
| 5/8 - 18 UNF | .5889 | .5949 | .5934 | .0003 | .0003 | 0°10' |
| 5/8 - 24 UNEF | .5979 | .6031 | .6018 | .0003 | .0003 | 0°15' |
| 11/16 - 24 UNEF | .6604 | .6656 | .6643 | .0003 | .0003 | 0°15' |
| 3/4 - 10 UNC | .6850 | .6927 | .6907 | .0003 | .0003 | 0°10' |
| 3/4 - 16 UNF | .7094 | .7159 | .7143 | .0003 | .0003 | 0°10' |
| 3/4 - 20 UNEF | .7175 | .7232 | .7218 | .0003 | .0003 | 0°15' |
| 13/16 - 20 UNEF | .7800 | .7857 | .7843 | .0003 | .0003 | 0°15' |
| 7/8 - 9 UNC | .8028 | .8110 | .8089 | .0003 | .0003 | 0°10' |
| 7/8 - 14 UNF | .8286 | .8356 | .8339 | .0003 | .0003 | 0°10' |
| 7/8 - 20 UNEF | .8425 | .8482 | .8468 | .0003 | .0003 | 0°15' |
| 15/16 - 20 UNEF | .9050 | .9109 | .9094 | .0003 | .0003 | 0°15' |
| 1”- 8 UNC | .9188 | .9276 | .9254 | .0004 | .0004 | 0°05' |
| 1”- 12 UNF | .9459 | .9535 | .9516 | .0003 | .0003 | 0°10' |
| 1”- 14 UNS | .9536 | .9609 | .9590 | .0003 | .0003 | 0°10' |
| 1”- 20 UNEF | .9675 | .9734 | .9719 | .0003 | .0003 | 0°15' |
| 1 1/16 - 12 UN | 1.0084 | 1.0158 | 1.0139 | .0003 | .0003 | 0°10' |
| 1 1/16 - 18 UNEF | 1.0264 | 1.0326 | 1.0310 | .0003 | .0003 | 0°10' |
| 1 1/8 - 7 UNC | 1.0322 | 1.0416 | 1.0393 | .0004 | .0004 | 0°05' |
| 1 1/8 - 12 UNF | 1.0709 | 1.0787 | 1.0768 | .0003 | .0003 | 0°10' |
| 1 1/8 - 18 UNEF | 1.0889 | 1.0951 | 1.0935 | .0003 | .0003 | 0°10' |
| 1 3/16 - 12 UN | 1.1334 | 1.1409 | 1.1390 | .0003 | .0003 | 0°10' |
| 1 3/16 - 18 UNEF | 1.1514 | 1.1577 | 1.1561 | .0003 | .0003 | 0°10' |
| 1 1/4 - 7 UNC | 1.1572 | 1.1668 | 1.1644 | .0004 | .0004 | 0°05' |
| 1 1/4 - 12 UNF | 1.1959 | 1.2039 | 1.2019 | .0003 | .0003 | 0°10' |
| 1 1/4 - 18 UNEF | 1.2139 | 1.2202 | 1.2186 | .0003 | .0003 | 0°10' |
| 1 5/16 - 12 UN | 1.2584 | 1.2659 | 1.2640 | .0003 | .0003 | 0°10' |
| 1 5/16 - 18 UNEF | 1.2764 | 1.2827 | 1.2811 | .0003 | .0003 | 0°10' |
| 1 3/8 - 6 UNC | 1.2667 | 1.2771 | 1.2745 | .0004 | .0004 | 0°05' |
| 1 3/8 - 12 UNF | 1.3209 | 1.3291 | 1.3270 | .0003 | .0003 | 0°10' |
| 1 3/8 - 18 UNEF | 1.3389 | 1.3452 | 1.3436 | .0003 | .0003 | 0°10' |
| 1 7/16 - 12 UN | 1.3834 | 1.3910 | 1.3891 | .0003 | .0003 | 0°10' |
| 1 7/16 - 18 UNEF | 1.4014 | 1.4079 | 1.4062 | .0003 | .0003 | 0°10' |
| 1 1/2 - 6 UNC | 1.3917 | 1.4022 | 1.3996 | .0004 | .0004 | 0°05' |
| 1 1/2 - 12 UNF | 1.4459 | 1.4542 | 1.4522 | .0003 | .0003 | 0°10' |
| 1 1/2 - 18 UNEF | 1.4639 | 1.4704 | 1.4687 | .0003 | .0003 | 0°10' |
How to Read the Standard Pitch Diameter Chart for Thread Plug Gages
To use the standard pitch diameter chart for thread plug gages, match the thread size you are working with to the chart's listed sizes. This will provide you with the go/no-go measurements necessary for ensuring your threads meet the specified tolerances for functionality and compatibility. It's a crucial step for quality control in manufacturing and engineering, helping prevent errors in thread sizing that could lead to part failure or incompatibility.
