Matching NC35 bolts

[fastdruid]

Ive used stainless allen key type bolts on my bikes for years with no issues, wheels on and off all the time. i just clean them up and put a drop of threadlock on em

You do know that standard stainless doesn't have the same tensile strength as carbon steel? If you're going to use it for brakes you need to ensure you get the decent stuff rather than just any old stainless cap screws.
I personally wouldn't risk it on something as important as brakes.

Of course brake components *do* have a fairly large safety margin designed in but even so....

Druid

[Drunkn Munky]

Thats quite worrying!!!!

Ive been using A2-70 grade, a quick google reveals they have a slightly lower tensile strengh than carbon steel

EDIT, just found this, could be helpfull, http://home.jtan.com/~joe/KIAT/kiat_2.htm" onclick="window.open(this.href);return false;
scroll down a bit for a table on tensile stregth of bolts, seems A4-80 grade stainless is as close as your going to get

[Cammo]

Ive used stainless allen key type bolts on my bikes for years with no issues, wheels on and off all the time. i just clean them up and put a drop of threadlock on em

+1 this is what I use on my roadbike. I personally don't think it matter too much if you do them up correctly the first time (but don't race at IoM like that!!).

I use genuine parts on my racebike, I never threadlock them as they're lockwired (FWIW I never threadlock disc bolts at all - overkill). From memory I think the nc30 bolts are waisted (thinner thread portion at the head end), so as said they aren't just a normal off the shelf fastener.

A neat solution for lockwiring that I've seen the top guys do is to use r-clips to go through the caliper bolt holes and just lockwire these r-clips together. Just as effective and it means you don't need to undo lockwire every time you change wheels/calipers. Neat, and passes scrutineering.

[fastdruid]

Thats quite worrying!!!!

Ive been using A2-70 grade, a quick google reveals they have a slightly lower tensile strengh than carbon steel

Yes but they don't tend to use plain 8.8 carbon steel for brake bolts!

More likely to use 10.9 or 12.9, from that table
12.9 12.9 Alloy Steel 1220 177,000 1100 160,000
A2-70 A2-70 302 Stainless 700 102,000 450 65,000

Both yield and tensile are about 1/2 that of 12.9!

Druid

[Drunkn Munky]

Youve convinced me........im off to tasty nuts for some proper bolts, better safe than sorry, its cheaper in the long run

[eden.kwok]

wow, those bolts arent cheap from tasty-nut at nearly 6 pounds a bolt......

[Drunkn Munky]

Is it just the caliper mounting bolts that need to be high tensile or do the 4 bolts that hold the 2 halfs together need to be high tensile too?

[fastdruid]

Is it just the caliper mounting bolts that need to be high tensile or do the 4 bolts that hold the 2 halfs together need to be high tensile too?

Well they should be...

I would at least use A4, chances are it will be totally and utterly fine even with A2 *but* I personally wouldn't risk it.

Druid

[eden.kwok]

Oh forgot to ask are the caliper bolts M8 x 1.25 x 25mm?

[Cammo]

Oh forgot to ask are the caliper bolts M8 x 1.25 x 25mm?

At a guess I think they are M8 x 1.5, but my memory gets away from me sometimes...