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is superseded by the American UNF Thread.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. To purchase a copy visit an Authorized Reseller.
Comments:
Original Posting: 2/28/2008
Last Revision: 2/12/2013
Error corrections in, or comments about, the above data can be sent to: office@gagecrib.com
Gage Crib Worldwide, Inc.
6701 Old 28th St SE, Suite B
Grand Rapids, MI 49546-6937
Phone: 001-616-954-6581 • Fax: 001-616-954-6583 CONTACT FORMS & INFO
