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TR1 front caliper bolts (SOLVED)

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TR1 front caliper bolts (SOLVED)

PostAuthor: Baldrick » Sat Feb 09, 2019 4:04 am

Hello all, anyone know the exact thread size for TR1 front caliper bolts.
I need 4 of these and would have an easier time if i knew the thread pitch etc.
Cheers in advance for any help.

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Re: TR1 front caliper bolts

PostAuthor: mark75 » Sun Feb 10, 2019 7:10 pm ... ke-caliper
shows it to be an M8 x 12mm bolt

M8 specs ---> ... eners.html

Understanding Metric Fasteners
Fastener Tech Data | Understanding Series Introduction

The size of a metric screw or bolt is specified as diameter, pitch and length, in millimeters (millimeters is abbreviated "mm"). For nuts, size will appear as diameter and pitch. There is an exception though—if pitch isn't specified, the fastener is coarse threaded. Consider this size…

M8-1.0 x 20

Here's what the description means…

M = Metric thread designation

8 = Nominal diameter, in millimeters

1.0 = Pitch (distance from thread to thread), in millimeters

20 = Length, in millimeters (see below)

This example illustrates how a coarse threaded screw may appear…

M12 x 25 = 12 mm diameter, coarse thread is assumed (1.75 mm), 25 mm long

M12 is a matching coarse threaded nut

(To avoid confusion, we always include the thread pitch for both coarse and fine metric fasteners.)

If you normally work with inch fasteners, pitch can be a little confusing—pitch is the distance between adjacent threads. In the example above, a pitch of 1.0 means that from one thread to the next thread, the distance is 1.0 millimeter. Inch fasteners are described as threads per inch, which is sometimes mistakenly called pitch. If you need to know the threads per inch of a metric fastener, first convert pitch from millimeters to inches (multiply by 0.03937), then divide 1 by that number.
Or, use the table below…

Table 1. Fastener thread pitch in millimeters and inches.

Pitch: Pitch: TPI:
(mm) (inches) Threads per Inch
0.2 0.0079 127.00
0.25 0.0098 101.60
0.3 0.0118 84.67
0.35 0.0138 72.57
0.4 0.0157 63.50
0.45 0.0177 56.44
0.5 0.0197 50.80
0.6 0.0236 42.33
0.7 0.0276 36.29
0.75 0.0295 33.87
0.8 0.0315 31.75
1.0 0.0394 25.40
1.25 0.0492 20.32
1.5 0.0591 16.93
1.75 0.0689 14.51
2.0 0.0787 12.70
2.5 0.0984 10.16
3.0 0.1181 8.47
3.5 0.1378 7.26
4.0 0.1575 6.35
4.5 0.1772 5.64
5.0 0.1969 5.08
5.5 0.2165 4.62
6.0 0.2362 4.23
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Re: TR1 front caliper bolts

PostAuthor: nanno » Mon Feb 11, 2019 1:05 am

Sorry Mark,

but that's definitely wrong. The bolts are M10-bolts, it's just a matter of the thread pitch.

Baldrick, as I said on some other communication channel - try the banjo bolt from the brake mastercylinder. If that one works, it's M10x1.25 .

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Re: TR1 front caliper bolts

PostAuthor: Baldrick » Mon Feb 11, 2019 4:57 am

Nice one Greg

Banjo bolt fits perfect, will try to source here now somewhere.

Cheers, solved

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