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Trouble finding bolts for my brackets

t.j. - 15/4/07 at 10:38 AM

Hey someone got a fabory no for me?

I'm looking for a bolt M12 which must go tru bracket lenght is 50 mm.

I want no tread in the brackets.

Then the only option is to use bolts with L=90 mm. But then i have to shorten them, which is no good for my Zinc..

So maybe someone been allready sorted this?

http://order.fabory.com/OpenCatalog.asp

[Edited on 15/4/07 by t.j.]

JoelP - 15/4/07 at 11:39 AM

you surely can find bolts with around 55 or 60mm unthreaded, then just put a few washers in to space the nut out to the thread?

blakep82 - 15/4/07 at 12:22 PM

bolts have an unthreaded part, and the thread on the end, set screws are bolts that are threaded all the way. namrick.com (.co.uk?) should be able to sort you with bolts the right length

MkIndy7 - 15/4/07 at 02:12 PM

Could you not use bolts the correct length and file/grind off the threads that would be inside the bracket so they'd clear.

Although that would remove the zinc plating it would only be on the part thats inside the bracket, and you could paint that part or cover it in grease to keep it protected

britishtrident - 15/4/07 at 02:27 PM

Dosen't work that way, you would need to use very thick spacers.

The bolt isn't a pivot ie each bolt it is done up tight so it grips the crush tube -- this applies to both poly and metalastic bushes, ie the location is provided by the friction joint.

[Edited on 15/4/07 by britishtrident]

t.j. - 15/4/07 at 06:01 PM

quote:
Originally posted by MkIndy7
Could you not use bolts the correct length and file/grind off the threads that would be inside the bracket so they'd clear.

Although that would remove the zinc plating it would only be on the part thats inside the bracket, and you could paint that part or cover it in grease to keep it protected

I think that works the best.
Taking M12x90 which has 50 mm untreaded and 40 mm tread.
Cutting 20 tread off will result in a nice bolt. spray some cold zinc on the cut.
Then choose a cap which fits on the nut.

JoelP - 15/4/07 at 07:40 PM

surely the thread is cut into the shaft so removing it will leave you just 10mm at the end, which is the end result of the thread wearing off anyway...

t.j. - 15/4/07 at 07:47 PM

quote:
Originally posted by JoelP
surely the thread is cut into the shaft so removing it will leave you just 10mm at the end, which is the end result of the thread wearing off anyway...

?

90-50= 40

40-20= 20 mm

I want in the bracket 12 mm, so no thread in the bracket.

The 20 mm is fine for the nut.

:-)

[Edited on 15/4/07 by t.j.]

JoelP - 15/4/07 at 07:53 PM

i meant 10mm diameter, which will rattle in the 12mm hole.

Angel Acevedo - 16/4/07 at 02:11 PM

.............

Then the only option is to use bolts with L=90 mm. But then i have to shorten them, which is no good for my Zinc..

So maybe someone been allready sorted this?

http://order.fabory.com/OpenCatalog.asp

[Edited on 15/4/07 by t.j.]

You could restore the zinc by electroplating.
this can be done at home with a 12 volt power supply, muriatic acid (Diluted) and a zinc anode...

NS Dev - 16/4/07 at 02:33 PM

why no thread inside the bracket, there is nothing wrong with this??

t.j. - 16/4/07 at 04:42 PM

quote:
Originally posted by NS Dev
why no thread inside the bracket, there is nothing wrong with this??

There where the bolt is in the bracket you want 12 mm on 12 mm. Not the thread which has not enough "hold"

MkIndy7 - 16/4/07 at 04:57 PM

Yup was thinking on the way home toady the method I suggested would leave only the diameter of the bottom of the thread and thus would be a loose fit

You could fill in the threads with chemical metal lol

JoelP - 16/4/07 at 05:30 PM

the outside of the thread is 12mm, if it was rotating it would wear faster but if nipped tight then you are ok, though IMHO it would be bad practice if avoidable.

NS Dev - 16/4/07 at 05:57 PM

Mine has threads in the bracket, that is the least of your worries!!!!

Its an M12 bolt!!!! Its so overengineered its madness!! That bolt will quite haplily rip the corner out of your chassis all on its own!

The threads are 12mm od anyway, and unless your bracket is less than 1.75mm thick, you will have two threads in contact with it anyway.

Its not the fit of the bolt that locates your suspension either, the clamp from the nut pinching the crush tube is what takes the force, technically you could put an 8mm bolt in there as long as you aligned it all in a straight line then torqued it up, nothing would move even if it never touched the bolt!

NS Dev - 16/4/07 at 05:58 PM

PS I use M12 capheads to hold on the rear trailing arms on my grasser, That is only 2 bolts taking all the arm load, including when I put it in the armco sideways at 60mph, and they have never moved at all (unlike the chassis) and they have threads in the bracket!

britishtrident - 17/4/07 at 02:44 PM

quote:
Originally posted by t.j.

quote:
Originally posted by NS Dev
why no thread inside the bracket, there is nothing wrong with this??

There where the bolt is in the bracket you want 12 mm on 12 mm. Not the thread which has not enough "hold"

NSDev is 100% right.

If you do it so the unthreaded portion is exactly the right size won't work the chances are the nut will become thread bound. The bracket must be squeezed in hard enough by the bolt to bight on the crush tube.

If it the crush tube or inner metal tube on rubber bush isn't gripped by the bracket you will get movement and fretting corrosion.

Just follow standard well proven engineering practice.

t.j. - 17/4/07 at 06:53 PM

Okay it make sense;

This is how i want to mount it, left and right of the crushtube two 2,5 mm washers.
The brackets are made of box 40x50x3 mm

I still think it is better to have no thread, if can be avoided. prettending if i'm not strong enough and tighten them too loose

brackets and bushes

[Edited on 17/4/07 by t.j.]