BSF

BRITISH STANDARD FINE

55 °

SIZE TPI EXTERNAL INTERNAL DRILL SIZE DRILL SIZE

BSF 55 MAJORS MINORS CLEARANCE HOLE TAPPED HOLE

INCH MM INCH MM INCH MM INCH MM

3/16 32 0.1875 4.76 0.1475 3.75 4.90 # 22 4.00

7/32 28 0.2188 5.56 0.1730 4.39 5.70 # 15 4.60

1/4 26 0.2500 6.35 0.2000 5.08 17/64 6.75 # 3 5.50

9/32 26 0.2800 7.14 0.2300 5.89 6.10

5/16 22 0.3125 7.94 0.2540 6.45 21/64 8.33 17/64 6.75

3/8 20 0.3750 9.53 0.3110 7.90 25/64 9.92 21/64 8.33

7/16 18 0.4375 11.11 0.3660 9.30 29/64 11.51 3/8 9.53

1/2 16 0.5000 12.70 0.4200 10.67 17/32 13.49 7/16 11.11

9/16 16 0.5625 14.29 0.4820 12.24 19/32 15.08 1/2 12.70

5/8 14 0.6250 15.88 0.5330 13.54 21/32 16.67 9/16 14.29

11/16 14 0.6875 17.46 0.5960 15.14 17.75 15.50

3/4 12 0.7500 19.05 0.6430 16.33 25/32 19.84 43/64 17.07

13/16 12 0.8100 20.64 0.7100 17.92 18.25

7/8 11 0.8750 22.23 0.7590 19.28 29/32 23.02 25/32 19.84

1 10 1.0000 25.40 0.8750 22.15 1 1/16 26.99 29/32 23.02

1 1/8 9 1.1250 28.58 0.9830 24.97 1 3/16 30.16 1 1/64 25.80

1 1/4 9 1.2500 31.75 1.1080 28.14 1 5/16 33.34 1 9/64 28.97

1 3/8 8 1.3750 34.93 1.2150 30.86 1 7/16 36.51 1 1/4 31.75

1 1/2 8 1.5000 38.10 1.3400 34.04 1 9/16 39.69 1 3/8 34.93

1 5/8 8 1.6300 41.30 1.4600 37.21 37.50

1 3/4 7 1.7500 44.45 1.5670 39.80 45.00 41.00

2 7 2.0000 50.80 1.8170 46.15 52.00 47.00

2 1/4 6 2.2500 57.15 2.0366 51.73 58.00 53.00

2 1/2 6 2.5000 63.50 2.2866 58.08 64.00 58.00

SIZE	TPI	EXTERNAL		INTERNAL		DRILL SIZE		DRILL SIZE
BSF 55		MAJORS		MINORS		CLEARANCE HOLE		TAPPED HOLE
		INCH	MM	INCH	MM	INCH	MM	INCH	MM
3/16	32	0.1875	4.76	0.1475	3.75		4.90	# 22	4.00
7/32	28	0.2188	5.56	0.1730	4.39		5.70	# 15	4.60
1/4	26	0.2500	6.35	0.2000	5.08	17/64	6.75	# 3	5.50
9/32	26	0.2800	7.14	0.2300	5.89				6.10
5/16	22	0.3125	7.94	0.2540	6.45	21/64	8.33	17/64	6.75
3/8	20	0.3750	9.53	0.3110	7.90	25/64	9.92	21/64	8.33
7/16	18	0.4375	11.11	0.3660	9.30	29/64	11.51	3/8	9.53
1/2	16	0.5000	12.70	0.4200	10.67	17/32	13.49	7/16	11.11
9/16	16	0.5625	14.29	0.4820	12.24	19/32	15.08	1/2	12.70
5/8	14	0.6250	15.88	0.5330	13.54	21/32	16.67	9/16	14.29
11/16	14	0.6875	17.46	0.5960	15.14		17.75		15.50
3/4	12	0.7500	19.05	0.6430	16.33	25/32	19.84	43/64	17.07
13/16	12	0.8100	20.64	0.7100	17.92				18.25
7/8	11	0.8750	22.23	0.7590	19.28	29/32	23.02	25/32	19.84
1	10	1.0000	25.40	0.8750	22.15	1 1/16	26.99	29/32	23.02
1 1/8	9	1.1250	28.58	0.9830	24.97	1 3/16	30.16	1 1/64	25.80
1 1/4	9	1.2500	31.75	1.1080	28.14	1 5/16	33.34	1 9/64	28.97
1 3/8	8	1.3750	34.93	1.2150	30.86	1 7/16	36.51	1 1/4	31.75
1 1/2	8	1.5000	38.10	1.3400	34.04	1 9/16	39.69	1 3/8	34.93
1 5/8	8	1.6300	41.30	1.4600	37.21				37.50
1 3/4	7	1.7500	44.45	1.5670	39.80		45.00		41.00
2	7	2.0000	50.80	1.8170	46.15		52.00		47.00
2 1/4	6	2.2500	57.15	2.0366	51.73		58.00		53.00
2 1/2	6	2.5000	63.50	2.2866	58.08		64.00		58.00