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redseal

Original Poster:

36 posts

92 months

[news] 
Thursday 16th August 2012 quote quote all
Having some 'fun' with some aftermarket wheels. Got what is probably a dumb question but after an hour of trawling the web i'm no closer to working it out.

Basic problem is i'm concerned there's insufficient thread showing on wheel stud to put enough rotations on the wheel nut to secure the wheel.

Best guidance i've managed to find is that MSA regs state minimum rotations as "1.5x the diameter of the stud". What i'm not sure of is the stud diameter or what unit should be used to measure it for the multiplier.

Stud is M12x 1.5 (I think). I believe the 12 indicates a 12mm diameter? So what does the 1.5 mean? (Is it the multiplier for the head size (12x1.5=18mm head?) or something else? [Edit, further investigation done - I believe this may be the thread pitch so thread pitch is 1.5mm?]

If i'm right about the 12mm then number of nut rotations is 12x1.5 which is 18, which is too many to make any sense.

The alternative is i'm completely misunderstanding the whole thing and "1.5x the diameter of the stud" has nothing to do with the # of rotations and could refer to the length of stud that should protude from the wheel for solid engagement. So 18mm. In this case where how to measure this accurately?

If you hadnt guessed, i'm confused as fook so all help appreciated - i'm tired of spinning my nuts! smile



Edited by redseal on Thursday 16th August 10:07

Adam205

546 posts

51 months

[news] 
Thursday 16th August 2012 quote quote all
M12x1.5 mean that the thread is 1.5mm pitch (ie one thread every 1.5mm).

1.5D is reasonable standard thread engagement but I would be happy running 1D and checking them regularly.

So for 1.5D that would mean 1.5*12/1.5=12 turns, for 1D that would be 1*12/1.5=8 turns.

Edited by Adam205 on Thursday 16th August 10:06

redseal

Original Poster:

36 posts

92 months

[news] 
Thursday 16th August 2012 quote quote all
Perfect, now it makes sense. Thanks Adam!

Snake the Sniper

2,235 posts

70 months

[news] 
Friday 17th August 2012 quote quote all
Depending upon your intended usage, having a thread or two clear of the nut is often advised so you can see if anything's coming undone.
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