FINE PITCH (BSF) BRITISH THREAD DATA CHART

 FINE PITCH (BSF) BRITISH THREAD DATA CHART

Whitworth Fine Thread BS 84
British Standard Fine Thread Series (parallel, cylindrical)
BSW and BSF are the Thread selections for commercial screws and nuts.
This fine thread, which is widespread in the British machine tool industry,
is superseded by the American UNF Thread.

THREAD DATA CHART:
British Thread (British Standard Fine) -- Fine Pitch
Nominal Size BSF	Thread Form Type	Major Diameter mm d=D	Pitch mm p	Threads per inch tpi	Pitch Diameter mm d2=D2	Minor Diameter Male Thd. d3	Thread Height H1	Tap Drill Diameter mm
3/16"	BSF	4.763	0.794	32	4.255	3.747	0.508	4.00
7/32"	BSF	5.556	0.907	28	4.975	4.394	0.581	4.60
1/4"	BSF	6.350	0.977	26	5.725	5.100	0.625	5.30
9/32"	BSF	7.142	0.977	26	6.518	5.893	0.625	6.10
5/16"	BSF	7.938	1.156	22	7.199	6.459	0.739	6.80
3/8"	BSF	9.525	1.27	20	8.712	7.899	0.813	8.30
7/16"	BSF	11.113	1.411	18	10.209	9.304	0.904	9.70
1/2"	BSF	12.700	1.588	16	11.684	10.668	1.017	11.10
9/16"	BSF	14.288	1.588	16	13.272	12.256	1.017	12.70
5/8"	BSF	15.875	1.814	14	14.712	13.549	1.162	14.00
11/16"	BSF	17.463	1.814	14	16.300	15.137	1.162	15.50
3/4"	BSF	19.050	2.117	12	17.693	16.336	1.355	16.75
13/16"	BSF	20.638	2.117	12	19.281	17.924	1.355	18.25
7/8"	BSF	22.225	2.309	11	20.747	19.269	1.479	19.75
1"	BSF	25.400	2.54	10	23.774	22.148	1.627	22.75
1-1/8"	BSF	28.575	2.822	9	26.769	24.963	1.807	26.50
1-1/4"	BSF	31.750	2.822	9	29.944	28.138	1.807	28.75
1-3/8"	BSF	34.925	3.175	8	32.893	30.861	2.033	31.50
1-1/2"	BSF	38.100	3.175	8	36.068	34.036	2.033	34.50
1-5/8"	BSF	41.275	3.175	8	39.243	37.211	2.033	38.00
1-3/4"	BSF	44.450	3.629	7	42.126	39.802	2.324	40.50
2"	BSF	50.800	3.629	7	48.476	46.152	2.324	47.00
2-1/4"	BSF	57.150	4.234	6	54.440	51.730	2.711	53.00
2-1/2"	BSF	63.500	4.234	6	60.790	58.080	2.711	59.00
2-3/4"	BSF	69.850	4.234	6	67.140	64.430	2.711	n/a
3"	BSF	76.200	5.08	5	72.946	69.692	3.253	n/a
3-1/4"	BSF	82.550	5.08	5	79.296	76.042	3.253	n/a
3-1/2"	BSF	88.900	5.645	4 1/2	85.285	81.670	3.614	n/a
3-3/4"	BSF	95.250	5.645	4 1/2	91.635	88.020	3.614	n/a
4"	BSF	101.600	5.645	4 1/2	97.985	94.370	3.614	n/a
4-1/4"	BSF	107.950	6.35	4	103.886	99.822	4.066	n/a

Disclaimer
This data is provided for general information only. The intention is to provide accurate information; regardless; errors may exist in the supplied information. If accuracy is critical, base your final decisions on the data provided in the root document: BS 84; which is a copyrighted document.