Whitworth Fine Thread BS 84

Whitworth Fine Thread BS 84

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 The Fine Thread, which is widespread in the Britisch machine tool industry, is superseded by the American UNF Thread.

Nominal Diameter	Major Diameter Inch	Major Diameter mm	Tapping Drill Size mm	TPI	Pitch mm
BSF 3/16"	3/16	4,763	3,747	32	0,794
BSF 7/32"	7/32	5,556	4,394	28	0,907
BSF 1/4"	1/4	6,350	5,100	26	0,977
BSF 9/32"	9/32	7,142	5,893	26	0,977
BSF 5/16"	5/16	7,938	6,459	22	1,154
BSF 3/8"	3/8	9,525	7,899	20	1,270
BSF 7/16"	7/16	11,113	9,304	18	1,411
BSF 1/2"	1/2	12,700	10,668	16	1,587
BSF 9/16"	9/16	14,288	12,256	16	1,587
BSF 5/8"	5/8	15,875	13,549	14	1,814
BSF 11/16"	11/16	17,463	15,137	14	1,814
BSF 3/4"	3/4	19,050	16,336	12	2,117
BSF 7/8"	7/8	22,225	19,269	11	2,309
BSF 1"	1	25,400	22,148	10	2,540
BSF 1 1/8"	1 1/8	28,575	24,963	9	2,822
BSF 1 1/4"	1 1/4	31,750	28,138	9	2,822
BSF 1 3/8"	1 3/8	34,925	30,861	8	3,175
BSF 1 1/2"	1 1/2	38,100	34,036	8	3,175
BSF 1 5/8"	1 5/8	41,275	37,211	8	3,175
BSF 1 3/4"	1 3/4	44,450	39,802	7	3,628
BSF 2"	2	50,800	46,152	7	3,628
BSF 2 1/4"	2 1/4	57,150	51,730	6	4,233
BSF 2 1/2"	2 1/2	63,500	58,080	6	4,233
BSF 2 3/4"	2 3/4	69,850	64,430	6	4,233
BSF 3"	3	76,200	69,692	5	5,080
BSF 3 1/4"	3 1/4	82,550	76,042	5	5,080
BSF 3 1/2"	3 1/2	88,900	81,670	4,5	5,644
BSF 3 3/4"	3 3/4	95,250	88,020	4,5	5,644
BSF 4"	4	101,600	94,370	4,5	5,644