Republic Drill - Technical Data - Taps & Dies - Minor Diameters of Tap Holes

Taps & Dies

Minor Diameters of Tap Holes

Figures Shown are Actual and Make No Allowance for the Tap Drill Cutting Oversize

Size	Threads Per Inch	Basic Minor Diam.	Minor Diameter of Tapped Holes Leaving Thread Engagement of:
Size	Threads Per Inch	Basic Minor Diam.	*83-1/3%	75%	70%	65%	60%
0	80	.0438	.0465	.0479	.0486	.0494	.0502
1	56	.0498	.0537	.0556	.0568	.0580	.0591
1	64	.0527	.0561	.0578	.0588	.0599	.0609
1	72	.0550	.0580	.0595	.0604	.0613	.0622
2	56	.0628	.0667	.0686	.0698	.0710	.0721
2	64	.0657	.0691	.0708	.0718	.0729	.0739
3	48	.0719	.0765	.0788	.0801	.0815	.0828
3	56	.0758	.0797	.0816	.0828	.0840	.0851
4	36	.0759	.0820	.0850	.0868	.0886	.0904
4	40	.0795	.0850	.0877	.0893	.0909	.0926
4	48	.0849	.0895	.0918	.0931	.0945	.0958
5	40	.0925	.0980	.1007	.1023	.1039	.1056
5	44	.0955	.1005	.1029	.1044	.1059	.1073
6	32	.0974	.1042	.1076	.1096	.1117	.1137
6	40	.1055	.1110	.1137	.1153	.1169	.1185
8	32	.1234	.1302	.1336	.1356	.1377	.1397
8	36	.1279	.1340	.1370	.1388	.1406	.1424
10	24	.1359	.1450	.1495	.1522	.1549	.1576
10	32	.1494	.1562	.1596	.1616	.1637	.1657
12	24	.1619	.1710	.1755	.1782	.1809	.1836
12	28	.1696	.1774	.1813	.1836	.1859	.1882
14	20	.1770	.1879	.1933	.1966	.1998	.2031
14	24	.1879	.1970	.2015	.2042	.2069	.2096
1/4	20	.1850	.1959	.2012	.2046	.2078	.2111
1/4	28	.2036	.2114	.2153	.2176	.2199	.2222
5/16	18	.2403	.2524	.2584	.2620	.2656	.2692
5/16	24	.2584	.2675	.2720	.2747	.2774	.2801
3/8	16	.2938	.3074	.3142	.3182	.3223	.3263
3/8	24	.3209	.3300	.3345	.3372	.3399	.3426
7/16	14	.3447	.3603	.3680	.3726	.3772	.3819
7/16	20	.3726	.3834	.3888	.3921	.3953	.3986
1/2	13	.4001	.4168	.4251	.4301	.4351	.4401
1/2	20	.4351	.4459	.4513	.4546	.4578	.4611
9/16	12	.4542	.4724	.4814	.4868	.4922	.4976
9/16	18	.4903	.5024	.5084	.5120	.5156	.5192
5/8	11	.5069	.5267	.5365	.5424	.5483	.5542
5/8	18	.5528	.5649	.5709	.5745	.5787	.5817
3/4	10	.6201	.6418	.6526	.6591	.6656	.6721
3/4	16	.6688	.6824	.6892	.6932	.6973	.7013
7/8	9	.7307	.7548	.7668	.7740	.7812	.7884
7/8	14	.7822	.7978	.8055	.8101	.8147	.8194
1	8	.8376	.8648	.8783	.8864	.8945	.9026
1	14	.9072	.9228	.9305	.9351	.9397	.9444
1-1/8	7	.9394	.9705	.9859	.9951	1.0044	1.0137
1-1/8	12	1.0168	1.0349	1.0439	1.0493	1.0547	1.0601
1-1/4	7	1.0644	1.0955	1.1109	1.1201	1.1294	1.1387
1-1/4	12	1.1418	1.1599	1.1689	1.1743	1.1797	1.1851
1-3/8	6	1.1585	1.1947	1.2127	1.2235	1.2343	1.2451
1-3/8	12	1.2668	1.2849	1.2939	1.2993	1.3047	1.3101
1-1/2	6	1.2835	1.3197	1.3377	1.3485	1.3593	1.3701
1-1/2	12	1.3918	1.4099	1.4189	1.4243	1.4297	1.4351

* This figure is the minimum minor diameter allowable on tapped holes as it is equal to the maximum minor diameter of the corresponding ring gauge.