Steels comparison

[hydorah]

Yeah man, you wanna use high tensile steel; 10.9 that type of thing - or Ti

Stainless steels is lacking in required tensile strength there's some fancy stuff for marine use etc... But you ain't getting that from bolts R us

By and large stainless presents a risk in high torque applications

Even the best is still not up there with the good old hi-ten stuff

http://www.anzor.co.nz/?t=40

 

[mikee]

true
but tit needs even more torque to achieve the same levels of compression
and yet we use aluminium in a stressed situation

 

[hydorah]

good point

That's an excellent point

It's all a balancing act tensile strength, hardness, ductility...

 

[mikee]

pretty shiney stainless sir love you loooong time
and with inteligent machining as light as ti

 

[raymondluxuryyacht]

Ok, so could you give us an idiots guide to what bolt materials might be fine in various bike situations ?

For example...
stem with four bolt face plate. Typical torque for faceplate bolts would be about 4-5nm. I am guessing you could get away with even aluminium in such an application, but there is no way I'd use aluminium bolts for the steerer clamp.

Bottle bosses....probably be fine with alumnium ?

Brake mounting bolts titanium or steel ok ?

Brake lever and gear lever mounts, titanium and steel ok ? but what about aluminium ?

Cable clamp bolts ?
Seat clamp bolts ?
Crank bolts ?
Jockey bolts ?

 

[hydorah]

pretty shiney stainless sir love you loooong time
and with inteligent machining as light as ti

I do love a bit of shiny Mr Mikey

It's chromium that makes stainless... erm stainless about 12% upwards

Chromium itself is hard, but brittle

But you can shop about and get the properties you are after from the different alloys available, which I guess you guys have done

At least it won't corrode away! If it ain't there any more it won't do anything for you

For brakes I go for chrome plated high tensile bolts and keep 'em clean

 

[hydorah]

Fastener choice

Park bike tools have a torque settings chart

But basically, in my opinion:

Cable clamp bolts - should'nt be over tightened anyway, only needs to grab the cable sufficiently not crush it to death

Seat clamp bolts - maybe... As the tube just needs to be compressed around the seat post, but there is some lateral force on a bolt too, so I wouldn't

Same with cattle head stems...

As you say front loader stems would probably be just fine, I have even considered using aluminium bolts - But ultimately dismissed the idea, just like you

Crank bolts - nah

Jockey bolts - Yep for sure

Brake and gear lever mounts - Deffo!

Brake bosses/pivots - no aluminium, maybe the highest tensile stainless you can find but no 'stainless' with no quoted grade

Bottle bosses? No way aluminium does not have sufficient tensile strength in the dimensions available to retain a beverage!!!

 

[mikee]

to be honest i wont use tit bolts in anything below m8
years of motorcycle racing has taught me that an hour trying to drill
out a titanium bolt far outweighs the 4 grams saved
the heads round out on soft Ti far easier than stainless or hi -tensile
steel
aluminium non stressed and non -critical parts only

to finish first ,first you gotta finish

stainless has the advantage over hi-ten of a nice finish , corrosion resistance

btw
why did you post in here ?

 

[hydorah]

haha!

I created a new thread by accident!

Some dude somewhere was talking about using aluminium for his brake bosses

 

[hydorah]

It was here

Here is the thread

http://www.retrobike.co.uk/forum/viewtopic.php?t=140430

God knows how I managed to create a new topic?