Home

BA
BSC
BSF
BSP
BSTP
BSW
CEI
UNC
UNF
ME
BSB

BSC (British Standard Cycle) Thread Data

This fine thread profile was formulated for, and is well suited to cycle and motorcycle applications. Its fine pitch, allows high torque settings, and resists the tendancy to loosen under vibration, the larger core diameter also gives greater shear strength. Most people think that all cycle threads are 26 tpi pitch. Whilst this is true of all the most popular sizes from 1/4" to 3/4" diameter, other pitches were also used as shown in the tables seen in the CEI section

We have numerous taps and dies in BSC with 20 tpi threads.

Angle of thread = 60o

BSC Thread Profile
Diameter
(Inches)
Threads
per inch
Pitch
(Inch)
Core
Diameter
(Inch)
Tapping Drill Size
0.125
(1/8th) inch
40 Tpi 0.025 0.0984 ins Number Drill 39
0.1004 inch
2.5mm
0.1563
5/32 inch
32 Tpi 0.0312 0.1231 ins Number Drill 30
0.126 inch
3.25mm
0.1875
(3/16) inch
32 Tpi 0.0312 0.1542 ins Number Drill 23
0.1562 inch
3.97mm
0.250
(1/4) inch
26 Tpi 0.0385 0.2091 ins Number Drill 3
0.2188 inch
5.56mm
0.281
(9/32) inch
26 Tpi 0.0385 0.2403 ins Letter Drill D
0.2441 inch
6.2 mm
0.3125
(5/16) inch
26 Tpi 0.0385 0.2715 ins Letter Drill J
0.2756 inch
7 mm
0.375
(3/8) inch
26 Tpi 0.0385 0.334 ins Letter Drill R
0.3368 inch
8.65 mm
0.4375
(7/16) inch
26 Tpi 0.0385 0.3965 ins Letter Drill X
0.3976 inch
10.1 mm
0.5
(1/2) inch
26 Tpi 0.0385 0.4590 ins 0.4606 inch
11.7 mm
0.5625
(9/16) inch
26 Tpi 0.0385 0.5215 ins 0.5156 (33/64) inch
13.1 mm
0.625
(5/8) inch
26 Tpi 0.0385 0.5840 ins 0.5906 inch
15 mm
0.6875
(11/16) inch
26 Tpi 0.0385 0.6465 ins 0.6496 inch
16.5 mm
1 inch 26 Tpi 0.0385 0.959 ins 0.9688 (31/32) inch
24.61.1 mm

BRITISH TOOLS & FASTENERS, LLC
7696 ROUTE 31, LYONS NY 14489
[email protected]
TEL- 315 946 9400 FAX - 315 946 9344

Sales Terms And Privacy Policy