Stainless steel front disc Allen bolts?
 

Anyone fitted them?

I have a set ready to fit, but haven't put them on yet.

I should say, I am aware of two things: the possible danger of "cathodic" corrosion from dissimilar metals (largely overcome by the application of Copaslip, IMO), and, secondly, the fact that stainless steel is less strong than the steel that bolts (and especially allen screws) are normally made from.
(Contrary to that, I'm also aware that in some circumstances, the plating process on "ordinary" steel bolts can do damage which can seriously reduce the strength of the fasteners. This *ought* not to happen, if the correct de-embrittlement processes are carried out...)

I am a design engineer by trade, and had actually wondered about doing a basic fatigue analysis. Only thing I'd need to know is the actual braking force (in kg or whatever). If anyone has any data on this, I'd be grateful to hear it.

My gut feeling, however, is that whatever shear stress is induced in the bolts by the the couple of the braking effect, it is fairly small and nowhere near the yield stress of even 316 stainless.

So has anyone fitted stainless bolts here, or have any other useful data/comments? I'd be interested to hear.


[edit]
I'd also add that I'd guess that the full strength of the stock fasteners (Grade 12.9?) would be unlikely to be fully utilised, becasue the tapping in the hub would probably fail before the screws did.

[Edited on 26-2-2005 by moto748]

You said it yourself "and, secondly, the fact that stainless steel is less strong than the steel that bolts (and especially allen screws) are normally made from"

Titanium works thou:D;)

I have used these sorts of bolts before. No sweat. But........... be very careful when you are removing them. As you have said, the material is not a tough, and I have found that the hex bits tend to ovalise (new, made up word) the broached hex in the screw/bolt.

Rgds, Rob

I have used both "normal" allen headed stanless bolts and torx type.I have only ever had problems with the allen type:

1:You can't torque them up properly 'cos the key normally starts to round out the socket
2:They are an absolute bitch to get back out.I had to use a chisel/punch/hammer/impact driver to get my twelve out.

When i used the torx ones,no probs at all torquing them up and absolutely no problem taking them out.I would advise against using the normal ones.

Give Nelly a shout,he has them.

Shazaam has spoken..........

http://217.199.188.40/xmb/viewthread...=9368#pid76885

and

http://217.199.188.40/xmb/viewthread...=7427#pid60474

I have S/S button head cap screws fitted to the front discs of my 998s without any problems and have also fitted them to my Jota without any problems!

are they torqued up and have you had to remove them yet?:(

Even the std ones I've just removed were a nightmare.

Sprayed with release fluid overnight.
One Allen key socket snapped.
Sadly ended up hammering an old Torq socket into the screws and using an impact driver finally got them out!!!

Even though everything would warm up together is there any mileage in bringing a wheel / item into the warm for a while I wonder?

Frank

Well as I said in my first post, I'm aware of the cathodic/galvanic whatever-you-want-to-call-it issue, but I've I've been putting stainless steel allen screws on my bikes since Triumph Bonneville primary chaincases in the Seventies, and can't say I've had too many problems with that.

Funny to see titanium mentioned. Titianium of course comes in various grades, but my understanding was that titanium bolts are around the same strength as stainless ones, and certainly not up to Grade 12.9 standards. If anyone has chapter and verse to show me different, I'd be interested to see.

Personally I can't say I've had any issues with ovalling of the recesses. of course, with stainless, as with titanium, there are better, and less good suppliers around.
I'm not at home to check the torque setting of the bolts in my manual (and does ducati.com even give this sort of info any more? It used to have torque settings and all sorts of useful data available when the 748/998 bikes were current), but as they're a tapping, rather than "nut and bolt", I'd be surprised if they're that high.


Jasper> What material are the torx screws you mention made of?

The Torx are stainless.