Steel Bolt Nut Threaded Fastener Hardness Force Metric Conversion Table Standards UNC

UNC, UNF and UNEF Thread Table

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SPEAK TO AN EXPERT

The table below shows the types of screw threads, sizes, and specifications of Unified Coarse (UNC), Unified Fine (UNF) and Unified Extra Fine (UNEF) threads.

Unified Coarse UNC Unified Fine UNF Thread

Thread sizes are not directly interchangeable. For guidance only.

UNC

Thread	Major Diameter	Thread Per Inch	Pitch Diameter	Minor Diameter Male Thread	Minor Diameter Female Thread
1	0.0730	64	0.0629	0.0544	0.0561
2	0.0860	56	0.0744	0.0648	0.0667
3	0.0990	48	0.0855	0.0741	0.0764
4	0.1120	40	0.0958	0.0822	0.0849
5	0.1250	40	0.1088	0.0952	0.0979
6	0.1380	32	0.1177	0.1008	0.1042
8	0.1640	32	0.1437	0.1268	0.1302
10	0.1900	24	0.1629	0.1404	0.1449
12	0.2160	24	0.1889	0.1664	0.1709
1/4	0.2500	20	0.2175	0.1905	0.1959
5/16	0.3125	18	0.2764	0.2464	0.2524
3/8	0.3750	16	0.3344	0.3005	0.3073
7/16	0.4375	14	0.3911	0.3525	0.3602
1/2	0.5000	13	0.4500	0.4084	0.4167
9/16	0.5625	12	0.5084	0.4633	0.4723
5/8	0.6250	11	0.5660	0.5168	0.5266
3/4	0.7500	10	0.6850	0.6309	0.6417
7/8	0.8750	9	0.8028	0.7427	0.7547
1	1.0000	8	0.9188	0.8512	0.8647
1-1/8	1.1250	7	1.0322	0.9549	0.9704
1 1/4	1.2500	7	1.1572	1.0799	1.0954
1-3/8	1.3750	6	1.2667	1.1766	1.1946
1 1/2	1.5000	6	1.3917	1.3016	1.3196
1 3/4	1.7500	5	1.6201	1.5119	1.5335
2	2.0000	4.5	1.8557	1.7353	1.7594
2 1/4	2.2500	4.5	2.1057	1.9853	2.0094
2 1/2	2.5000	4	2.3376	2.2023	2.2294
2 3/4	2.7500	4	2.5876	2.4523	2.4794
3	3.0000	4	2.8376	2.7023	2.7294
3 1/4	3.2500	4	3.0876	2.9523	2.9794
3 1/2	3.5000	4	3.3376	3.2023	3.2294
3 3/4	3.7500	4	3.5876	3.4523	3.4794
4	4.0000	4	3.8376	3.7023	3.7294

UNF

Thread	Major Diameter	Thread per Inch	Pitch Diameter	Minor Diameter Male Thread	Minor Diameter Female Thread
0	0.0600	80	0.0519	0.0451	0.0465
1	0.0730	72	0.0640	0.0565	0.0580
2	0.0860	64	0.0759	0.0674	0.0691
3	0.0990	56	0.0874	0.0778	0.0797
4	0.1120	48	0.0985	0.0871	0.0894
5	0.1250	44	0.1102	0.0979	0.1004
6	0.1380	40	0.1218	0.1082	0.1109
8	0.1640	36	0.1460	0.1309	0.1339
10	0.1900	32	0.1697	0.1528	0.1562
12	0.2160	28	0.1928	0.1734	0.1773
1/4	0.2500	28	0.2268	0.2074	0.2113
5/16	0.3125	24	0.2854	0.2629	0.2674
3/8	0.3750	24	0.3479	0.3254	0.3299
7/16	0.4375	20	0.4050	0.3780	0.3834
1/2	0.5000	20	0.4675	0.4405	0.4459
9/16	0.5625	18	0.5264	0.4964	0.5024
5/8	0.6250	18	0.5889	0.5589	0.5649
3/4	0.7500	16	0.7094	0.6763	0.6823
7/8	0.8750	14	0.8286	0.7900	0.7977
1	1.0000	12	0.9459	0.9001	0.9098
1 1/8	1.1250	12	1.0709	1.0258	1.0348
1 1/4	1.2500	12	1.1959	1.1508	1.1598
1 3/8	1.3750	12	1.3209	1.2758	1.2848
1 1/2	1.5000	12	1.4459	1.4008	1.4098

UNEF

Thread	Major Diameter	Thread Per Inch	Pitch Diameter	Minor Diameter Male Thread	Minor Diameter Female Thread
No. 12	0.2160	32	0.1957	0.1788	0.1822
1/4	0.2500	32	0.2297	0.2128	0.2162
5/16	0.3125	32	0.2922	0.2753	0.2787
3/8	0.3750	32	0.3547	0.3378	0.3412
7/16	0.4375	28	0.4143	0.3949	0.3988
1/2	0.5000	28	0.4768	0.4574	0.4613
9/16	0.5625	24	0.5354	0.5129	0.5174
5/8	0.6250	24	0.5979	0.5754	0.5799
11/16	0.6875	24	0.6604	0.6379	0.6424
3/4	0.7500	20	0.7175	0.6905	0.6959
13/16	0.8125	20	0.7800	0.7530	0.7584
7/8	0.8750	20	0.8425	0.8155	0.8209
15/16	0.9375	20	0.9050	0.8780	0.8834
1	1.0000	20	0.9675	0.9405	0.9459
1 1/16	1.0625	18	1.0264	0.9964	1.0024
1 1/8	1.1250	18	1.0889	1.0589	1.0649
1 3/16	1.1875	18	1.1514	1.1214	1.1274
1 1/4	1.2500	18	1.2139	1.1839	1.1899
1 5/16	1.3125	18	1.2764	1.2464	1.2524
1 3/8	1.3750	18	1.3389	1.3089	1.3149
1 7/16	1.4375	18	1.4014	1.3714	1.3774
1 1/2	1.5000	18	1.4639	1.4339	1.4399
1 9/16	1.5625	18	1.5264	1.4964	1.5024
1 5/8	1.6250	18	1.5889	1.5589	1.5649
1 11/16	1.6875	18	1.6514	1.6214	1.6274

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