What Does Uns Stand for on a Thread

UNS screw threads that have special combinations of diameter and pitch with tolerance to Unified formulation have the basic form designation set out first followed always by the limits of size.

#10 - 1/4" 5/16" - 1/2" 9/16" - 1" 1 1/8"- 1 7/8" 2"- 2 1/2" 2 3/4" - 3 3/4" 4" - 6"

Nominal Size	External (b)								Internal (b)
Threads per Inch and Series Designation	Class	Allowance	Major Diameter			Minor Diameter		UNR Minor Dia.,c Max (Ref.)	Class	Minor Diameter		Pitch Diameter		Major Diameter
			Max (d)	Min	Min (e)	Max (d)	Min			Min	Max	Min	Max	Min
#10 - 28UNS	2A	0.001	4.801	4.636	. . .	4.211	4.128	3.719	2B	3.835	4.064	4.237	4.346	4.826
#10 - 36UNS	2A	0.0009	4.803	4.663	. . .	4.346	4.27	3.962	2B	4.064	4.216	4.369	4.468	4.826
#10 - 40UNS	2A	0.0009	4.803	4.674	. . .	4.392	4.318	4.044	2B	4.14	4.293	4.415	4.509	4.826
#10 - 48UNS	2A	0.0008	4.806	4.691	. . .	4.463	4.397	4.176	2B	4.242	4.369	4.483	4.569	4.826
#10 - 56UNS	2A	0.0007	4.808	4.704	. . .	4.514	4.45	4.27	2B	4.343	4.445	4.531	4.613	4.826
#12 - 36UNS	2A	0.0009	5.464	5.324	. . .	5.006	4.93	4.625	2B	4.724	4.877	5.029	5.128	5.486
#12 - 40UNS	2A	0.0009	5.464	5.334	. . .	5.052	4.978	4.661	2B	4.801	4.953	5.075	5.169	5.486
#12 - 48UNS	3A	0.0008	5.466	5.352	. . .	5.123	5.057	4.836	2B	4.902	5.029	5.144	5.23	5.486
#12 - 56UNS	2A	0.0007	5.469	5.364	. . .	5.174	5.11	4.93	2B	5.004	5.105	5.192	5.273	5.486
1/4" - 24 UNS	2A	0.0011	6.322	6.139	. . .	5.634	5.54	5.062	2B	5.207	5.461	5.662	5.784	6.35
1/4" - 24 UNS	2A	0.001	6.325	6.154	. . .	5.712	5.624	5.204	2B	5.334	5.563	5.738	5.852	6.35
1/4" - 24 UNS	1A	0.001	6.325	6.076	. . .	5.735	5.608	5.243	1B	5.359	5.588	5.761	5.926	6.35
1/4" - 24 UNS	2A	0.001	6.325	6.16	. . .	5.735	5.652	5.243	2B	5.359	5.588	5.761	5.87	6.35
1/4" - 24 UNS	3A	0	6.35	6.185	. . .	5.761	5.697	5.268	3B	5.359	5.563	5.761	5.842	6.35
1/4" - 36 UNS	2A	0.0009	6.327	6.187	. . .	5.87	5.791	5.489	2B	5.588	5.74	5.893	5.994	6.35
1/4" - 40 UNS	2A	0.0009	6.327	6.198	. . .	5.916	5.842	5.57	2B	5.664	5.817	5.939	6.035	6.35
1/4" - 48UNS	2A	0.0008	6.33	6.215	. . .	5.987	5.918	5.697	2B	5.766	5.893	6.007	6.099	6.35
1/4" - 56 UNS	2A	0.0008	6.33	6.226	. . .	6.035	5.969	5.791	2B	5.867	5.969	6.055	6.139	6.35
5/16" - 27 UNS	2A	0.001	7.912	7.742	. . .	7.3	7.211	6.792	2B	6.909	7.137	7.325	7.44	7.938
5/16" - 36 UNS	2A	0.0009	7.915	7.775	. . .	7.457	7.379	7.074	2B	7.163	7.341	7.48	7.582	7.938
5/16" - 40 UNS	2A	0.0009	7.915	7.785	. . .	7.503	7.43	7.158	2B	7.239	7.391	7.526	7.623	7.938
5/16" - 48UNS	2A	0.0008	7.917	7.803	. . .	7.574	7.506	7.287	2B	7.366	7.493	7.595	7.686	7.938
3/8" - 18UNS	2A	0.0013	9.492	9.271	. . .	8.575	8.466	7.813	2B	8.001	8.331	8.608	8.75	9.525
3/8" - 27 UNS	2A	0.0011	9.497	9.327	. . .	8.885	8.793	8.377	2B	8.509	8.738	8.913	9.032	9.525
3/8" - 36 UNS	2A	0.001	9.5	9.36	. . .	9.042	8.961	8.659	2B	8.763	8.941	9.068	9.174	9.525
3/8" - 40 UNS	2A	0.0009	9.502	9.373	. . .	9.091	9.012	8.745	2B	8.839	8.992	9.114	9.215	9.525
0.390" - 27 UNS	2A	0.0011	9.878	9.708	. . .	9.266	9.174	8.758	2B	8.89	9.119	9.294	9.413	9.906
7/16" - 18UNS	2A	0.0013	11.079	10.859	. . .	10.163	10.053	9.401	2B	9.576	9.906	10.196	10.338	11.113
7/16" - 24 UNS	2A	0.0011	11.085	10.902	. . .	10.396	10.3	9.825	2B	9.957	10.211	10.424	10.549	11.113
7/16" - 27 UNS	2A	0.0011	11.085	10.914	. . .	10.472	10.381	9.964	2B	10.084	10.312	10.5	10.62	11.113
1/2" - 12UNS	2A	0.0016	12.659	12.37	. . .	11.285	11.148	10.14	2B	10.414	10.871	11.326	11.504	12.7
1/2" - 12UNS	3A	0	12.7	12.41	. . .	11.326	11.224	10.18	3B	10.414	10.726	11.326	11.458	12.7
1/2" - 14 UNS	2A	0.0015	12.662	12.4	. . .	11.483	11.356	10.503	2B	10.744	11.125	11.521	11.687	12.7
1/2" - 18UNS	2A	0.0013	12.667	12.446	. . .	11.75	11.638	10.988	2B	11.176	11.506	11.783	11.93	12.7
1/2" - 24 UNS	2A	0.0012	12.67	12.487	. . .	11.981	11.882	11.41	2B	11.557	11.811	12.012	12.141	12.7
1/2" - 27 UNS	2A	0.0011	12.672	12.502	. . .	12.06	11.966	11.552	2B	11.684	11.913	12.088	12.21	12.7
9/16" -14 UNS	2A	0.0015	14.249	13.988	. . .	13.071	12.944	12.09	2B	12.319	12.725	13.109	13.274	14.288
9/16" -27 UNS	2A	0.0011	14.26	14.089	. . .	13.647	13.553	13.139	2B	13.259	13.487	13.675	13.797	14.288
5/8" - 14 UNS	2A	0.0015	15.837	15.575	. . .	14.658	14.529	13.678	2B	13.919	14.326	14.696	14.864	15.875
5/8" - 27 UNS	2A	0.0011	15.847	15.677	. . .	15.235	15.138	14.727	2B	14.859	15.088	15.263	15.39	15.875
3/4" - 14 UNS	2A	0.0015	19.012	18.75	. . .	17.833	17.704	16.853	2B	17.094	17.475	17.871	18.042	19.05
3/4" - 18UNS	2A	0.0014	19.014	18.793	. . .	18.098	17.981	17.336	2B	17.526	17.856	18.133	18.285	19.05
3/4" - 24 UNS	2A	0.0012	19.02	18.837	. . .	18.331	18.227	17.76	2B	17.907	18.161	18.362	18.496	19.05
3/4" - 24 UNS	2A	0.0012	19.02	18.849	. . .	18.407	18.308	17.899	2B	18.034	18.263	18.438	18.567	19.05
7/8" - 10 UNS	2A	0.0018	22.179	21.852	. . .	20.528	20.376	19.157	2B	19.482	20.015	20.574	20.772	22.225
7/8" - 18UNS	2A	0.0014	22.189	21.968	. . .	21.273	21.156	20.511	2B	20.701	21.031	21.308	21.46	22.225
7/8" - 24 UNS	2A	0.0012	22.195	22.012	. . .	21.506	21.402	20.935	2B	21.082	21.336	21.537	21.671	22.225
7/8" - 27 UNS	2A	0.0012	22.195	22.024	. . .	21.582	21.483	21.074	2B	21.209	21.438	21.613	21.742	22.225
1" - 10 UNS	2A	0.0018	25.354	25.027	. . .	23.703	23.546	22.332	2B	22.657	23.19	23.749	23.952	25.4
1" - 14 UNSf	1A	0.0017	25.357	24.963	. . .	24.178	23.965	23.195	1B	23.444	23.825	24.221	24.498	25.4
1" - 14 UNSf	2A	0.0017	25.357	25.095	. . .	24.178	24.036	23.195	2B	23.444	23.825	24.221	24.407	25.4
1" - 14 UNSf	3A	0	25.4	25.138	. . .	24.221	24.115	23.238	3B	23.444	23.66	24.221	24.359	25.4
1" - 18UNS	2A	0.0014	25.364	25.143	. . .	24.448	24.328	23.686	2B	23.876	24.206	24.483	24.641	25.4
1" - 24 UNS	2A	0.0013	25.367	25.184	. . .	24.679	24.572	24.107	2B	24.257	24.511	24.712	24.851	25.4
1" - 27 UNS	2A	0.0012	25.37	25.199	. . .	24.757	24.656	24.249	2B	24.384	24.613	24.788	24.92	25.4
1 1/8" - 10 UNS	2A	0.0018	28.529	28.202	. . .	26.878	26.721	25.507	2B	25.832	26.365	26.924	27.127	28.575
1 1/8" - 14 UNS	2A	0.0016	28.534	28.273	. . .	27.356	27.221	26.375	2B	26.619	27.026	27.396	27.572	28.575
1 1/8" - 24 UNS	2A	0.0013	28.542	28.359	. . .	27.854	27.747	27.285	2B	27.432	27.686	27.887	28.026	28.575
1 1/4" -10 UNS	2A	0.0019	31.702	31.374	. . .	30.051	29.891	28.679	2B	29.007	29.54	30.099	30.307	31.75
1 1/4" -14 UNS	2A	0.0016	31.709	31.448	. . .	30.531	30.394	29.55	2B	29.794	30.175	30.571	30.749	31.75
1 1/4" -24 UNS	2A	0.0013	31.717	31.534	. . .	31.029	30.919	30.457	2B	30.607	30.861	31.062	31.204	31.75
1 3/8" - 10 UNS	2A	0.0019	34.877	34.549	. . .	33.226	33.066	31.854	2B	32.182	32.715	33.274	33.482	34.925
1 3/8" - 14 UNS	2A	0.0016	34.884	34.623	. . .	33.706	33.569	32.725	2B	32.969	33.376	33.746	33.924	34.925
1 3/8" - 24 UNS	2A	0.0013	34.892	34.709	. . .	34.204	34.094	33.632	2B	33.782	34.036	34.237	34.379	34.925
1 1/2" - 10 UNS	2A	0.0019	38.052	37.724	. . .	36.401	36.238	35.029	2B	35.357	35.89	36.449	36.66	38.1
1 1/2" - 14 UNS	2A	0.0017	38.057	37.795	. . .	36.878	36.739	35.898	2B	36.144	36.525	36.921	37.104	38.1
1 1/2" - 24 UNS	2A	0.0013	38.067	37.884	. . .	37.379	37.267	36.807	2B	36.957	37.211	37.412	37.559	38.1
1 5/8" - 10 UNS	2A	0.0019	41.227	40.899	. . .	39.576	39.413	38.204	2B	38.532	39.065	39.624	39.835	41.275
1 5/8" - 14 UNS	2A	0.0017	41.232	40.97	. . .	40.053	39.914	39.073	2B	39.319	39.726	40.096	40.279	41.275
1 5/8" - 24 UNS	2A	0.0013	41.242	41.059	. . .	40.554	40.442	39.982	2B	40.132	40.386	40.587	40.734	41.275
1 3/4" - 10 UNS	2A	0.0019	44.402	44.074	. . .	42.751	42.586	41.379	2B	41.707	42.24	42.799	43.012	44.45
1 3/4" - 14 UNS	2A	0.0017	44.407	44.145	. . .	43.228	43.086	42.245	2B	42.494	42.875	43.271	43.457	44.45
1 3/4" - 18UNS	2A	0.0015	44.412	44.191	. . .	43.495	43.365	42.733	2B	42.926	43.256	43.533	43.701	44.45
1 7/8" - 10 UNS	2A	0.0019	47.577	47.249	. . .	45.926	45.761	44.554	2B	44.882	45.415	45.974	46.187	47.625
1 7/8" - 14 UNS	2A	0.0017	47.582	47.32	. . .	46.403	46.261	45.423	2B	45.669	46.076	46.446	46.632	47.625
1 7/8" - 18UNS	2A	0.0015	47.587	47.366	. . .	46.67	46.54	45.908	2B	46.101	46.431	46.708	46.876	47.625
2" - 10 UNS	2A	0.002	50.749	50.422	. . .	49.098	48.933	47.727	2B	48.057	48.59	49.149	49.365	50.8
2" - 14 UNS	2A	0.0017	50.757	50.495	. . .	49.578	49.433	48.598	2B	48.844	49.225	49.621	49.809	50.8
2" - 18UNS	2A	0.0015	50.762	50.541	. . .	49.845	49.715	49.083	2B	49.276	49.606	49.883	50.053	50.8
2 1/16" - 16UNS	2A	0.0016	52.347	52.108	. . .	51.316	51.178	50.455	2B	50.673	51.029	51.356	51.534	52.388
2 1/16" - 16UNS	3A	0	52.388	52.149	. . .	51.356	51.255	50.495	3B	50.673	50.884	51.356	51.488	52.388
2 3/16" UNS	2A	0.0016	55.522	55.283	. . .	54.491	54.353	53.63	2B	53.848	54.204	54.531	54.709	55.563
2 3/16" UNS	3A	0	55.563	55.324	. . .	54.531	54.427	53.67	3B	53.848	54.059	54.531	54.663	55.563
2 1/4" - 10 UNS	2A	0.002	57.099	56.772	. . .	55.448	55.283	54.077	2B	54.407	54.94	55.499	55.715	57.15
2 1/4" - 14 UNS	2A	0.0017	57.107	56.845	. . .	55.928	55.783	54.948	2B	55.194	55.575	55.971	56.159	57.15
2 1/4" - 18UNS	2A	0.0015	57.112	56.891	. . .	56.195	56.065	55.433	2B	55.626	55.956	56.233	56.403	57.15
2 5/16" - 16UNS	2A	0.0017	58.694	58.456	. . .	57.663	57.523	56.802	2B	57.023	57.379	57.706	57.889	58.738
2 5/16" - 16UNS	3A	0	58.738	58.499	. . .	57.706	57.602	56.845	3B	57.023	57.234	57.706	57.843	58.738
2 7/16" - 16UNS	2A	0.0017	61.869	61.631	. . .	60.838	60.698	59.977	2B	60.198	60.554	60.881	61.064	61.913
2 7/16" - 16UNS	3A	0	61.913	61.674	. . .	60.881	60.777	60.02	3B	60.198	60.409	60.881	61.018	61.913
2 1/2" - 10 UNS	2A	0.002	63.449	63.122	. . .	61.798	61.628	60.427	2B	60.757	61.29	61.849	62.07	63.5
2 1/2" - 14 UNS	2A	0.0017	63.457	63.195	. . .	62.278	62.131	61.298	2B	61.544	61.925	62.321	62.514	63.5
2 1/2" - 18UNS	2A	0.0016	63.459	63.238	. . .	62.542	62.408	61.78	2B	61.976	62.306	62.583	62.758	63.5
2 3/4" - 10 UNS	2A	0.002	69.799	69.472	. . .	68.148	67.978	66.777	2B	67.107	67.64	68.199	68.42	69.85
2 3/4" - 14 UNS	2A	0.0017	69.807	69.545	. . .	68.628	68.481	67.648	2B	67.894	68.275	68.671	68.864	69.85
2 3/4" - 18UNS	2A	0.0016	69.809	69.588	. . .	68.892	68.758	68.13	2B	68.326	68.656	68.933	69.108	69.85
3" - 10 UNS	2A	0.002	76.149	75.822	. . .	74.498	74.325	73.127	2B	73.457	73.99	74.549	74.775	76.2
3" - 14 UNS	2A	0.0018	76.154	75.893	. . .	74.976	74.826	73.995	2B	74.244	74.625	75.021	75.217	76.2
3" - 18UNS	2A	0.0016	76.159	75.938	. . .	75.242	75.105	74.48	2B	74.676	75.006	75.283	75.461	76.2
3 1/4" - 10 UNS	2A	0.002	82.499	82.172	. . .	80.848	80.675	79.477	2B	79.807	80.34	80.899	81.125	82.55
3 1/4" - 14 UNS	2A	0.0018	82.504	82.243	. . .	81.326	81.176	80.345	2B	80.594	80.975	81.371	81.567	82.55
3 1/4" - 18UNS	2A	0.0016	82.509	82.288	. . .	81.592	81.455	80.83	2B	81.026	81.356	81.633	81.811	82.55
3 1/2" - 10 UNS	2A	0.0021	88.847	88.519	. . .	87.196	87.02	85.824	2B	86.157	86.69	87.249	87.478	88.9
3 1/2" - 14 UNS	2A	0.0018	88.854	88.593	. . .	87.676	87.521	86.695	2B	86.944	87.325	87.721	87.922	88.9
3 1/2" - 18UNS	2A	0.0017	88.857	88.636	. . .	87.94	87.8	87.178	2B	87.376	87.706	87.983	88.166	88.9
3 3/4" - 10 UNS	2A	0.0021	95.197	94.869	. . .	93.546	93.37	92.174	2B	92.507	93.04	93.599	93.828	95.25
3 3/4" - 14 UNS	2A	0.0018	95.204	94.943	. . .	94.026	93.871	93.045	2B	93.294	93.675	94.071	94.272	95.25
3 3/4" - 18UNS	2A	0.0017	95.207	94.986	. . .	94.29	94.15	93.528	2B	93.726	94.056	94.333	94.516	95.25
4" - 10 UNS	2A	0.0021	101.547	101.219	. . .	99.896	99.718	98.471	2B	98.857	99.39	99.949	100.18	101.6
4" - 14 UNS	2A	0.0018	101.554	101.293	. . .	100.376	100.218	99.395	2B	99.644	100.025	100.421	100.625	101.6
4 1/4" - 10 UNS	2A	0.0021	107.897	107.569	. . .	106.246	106.068	104.874	2B	105.207	105.74	106.299	106.53	107.95
4 1/4" - 14 UNS	2A	0.0018	107.904	107.643	. . .	106.726	106.568	105.745	2B	105.994	106.375	106.771	106.975	107.95
4 1/2" - 10 UNS	2A	0.0021	114.247	113.919	. . .	112.596	112.418	111.224	2B	111.557	112.09	112.649	112.88	114.3
4 1/2" - 14 UNS	2A	0.0018	114.254	113.993	. . .	113.076	112.918	112.095	2B	112.344	112.725	113.121	113.325	114.3
5 3/4" - 10UNS	2A	0.0022	145.994	145.666	. . .	144.343	144.155	142.972	2B	143.307	143.84	144.399	144.643	146.05
5 3/4" - 14 UNS	2A	0.002	145.999	145.738	. . .	144.821	144.656	143.84	2B	144.094	144.475	144.871	145.087	146.05
6" - 10 UNS	2A	0.0022	152.344	152.016	. . .	150.693	150.505	149.322	2B	149.657	150.19	150.749	150.993	152.4
6" - 14 UNS	2A	0.002	152.349	152.088	. . .	151.171	151.006	150.19	2B	150.444	150.825	151.221	151.437	152.4

What Does Uns Stand for on a Thread

Source: https://torqbolt.com/uns-unified-national-thread-dimensions-specifications

Share this post