Caliper joining bolt replacement

[Slide Panda]

My buddy was getting down to some work on his track 749 that included splitting the calipers so he could clean the pistons.  Of course he tells me all this too late, as one doesn't need to split the calipers for this... And he stripped the head of one of the bolts that joins the halves by the time he gets around to me

Is there any reason that one should not use a 18-8 stainless steel bolt as a replacement? The stock ones seem to be steel, but with some treating or shot peening perhaps.

If the 18-8 is a bad idea, please tell me why as I'd be curious and what the proper item is

[oldndumb]

I don't know the bolt spec but do know that BellisiMoto sells ProTi replacements for them. Yoyodyne might also be a resource for the steel ones.

[Slide Panda]

Thanks but the ones on bellisimoto are caliper mounting bolts. The question is about the bolts that join the two halves of these calipers.

Didn't spot anything on Yoyodyne - had already checked. That was my first stop

[oldndumb]

I understood which ones you meant.

Although Bellisimoto used to have a pic of them, I failed to verify that they still do. I admittedly do not remember which model they had pictured. I know that ProTi makes bolts for that application and easily verified with a Google image search.

If it were me, I would call Bellisimoto and ask them to order them. I have tried to order directly from ProTi before and it is sort of a clunky process. I understand that ProTi has improved their site so you might be able to find them listed. Of course, diameter and length need to be specified/verified.

Edit: Apologize for ignoring the gist of your original question. As I remember it, a rule of thumb is that an 18-1 SS bolt is roughly equivalent to a Grade 2 SAE bolt. Several sites have charts. One site that I keep going back to for fastener info is http://mdmetric.com

Best way to order small lots is to call direct.

[DarkMonster620]

check with TPO . . .

[ducatiz]

The correct bolt is at least a 10.9 metric alloy with antirust coating such as dacromet or yellow cadmium. 

If you must use stainless, do not use less than an A4.  A4 has similar properties to a 10.9 metric but is not as strong.

18-8 is not a metric spec, that is a common SAE spec and is somewhat comparable to an A2 stainless, which is approximately like an 8.8 metric.  I would not use that for anything where heat and stress are involved.

[Slide Panda]

ProTi = ProBolt? Or no?

'Tiz do you know of a vendor for such bolts? My go to for misc bolts has  been bolt depot which offers 18-8.  McMaster offers 316 and 18-8 in metric sizes but nothing so special as you're calling out

[Rudemouthsky]

The correct bolt is at least a 10.9 metric alloy with antirust coating such as dacromet or yellow cadmium. 

If you must use stainless, do not use less than an A4.  A4 has similar properties to a 10.9 metric but is not as strong.

18-8 is not a metric spec, that is a common SAE spec and is somewhat comparable to an A2 stainless, which is approximately like an 8.8 metric.  I would not use that for anything where heat and stress are involved.

The 316 SS bolts I've ordered from McMaster all have been stamped A4. A lot of venders use the terms 316L and 18-8 interchangeably with A2/A4 respectively, it's misleading because all 300 series SS is 18-8, that's a number that describes the mixture of the alloy, not any kind of hardness/corrossion resistance rating. Searching for "marine grade stainless" brings up more results that are specifically designated as A4.

[ducatiz]

ProTi = ProBolt? Or no?

'Tiz do you know of a vendor for such bolts? My go to for misc bolts has  been bolt depot which offers 18-8.  McMaster offers 316 and 18-8 in metric sizes but nothing so special as you're calling out

mdmetric.com has most of them or alternatives.

they also stock dacromet coated, which is a type of exotic dry lube / anti corrosive coating that would make Dr Who jealous.

you have to suffer their website.  oh god it is awful.  and you have to buy in minimum 100 quantities for many items.. it's a huge down but it's the only place to get some of this stuff.

here is a 12.9 rated bolt with dacromet coating.. 



a box of 100 of them sized M8 and 20mm long is $36.75

http://www.nofmetalcoatings.com/europe/en/coatings/dacromet/dacromet.xhtml

Dacromet is like a miracle coating.  Use a dacromet bolt for 20 years, then pull it out and reuse it another 50.  it completely prevents stress and corrosion.

[Howie]

I find it strange manufacturers are not using Dacromet coatings on fasteners and brackets.  Can't be that costly if it is on this complete trailer set  http://www.sturdybuiltonline.com/Kodiak-Trailer-Slip-on-Disc-Brake-Kit-Dacromet-Stainless-5-Bolt_p_764.html

[oldndumb]

.....
you have to suffer their website.  oh god it is awful.  and you have to buy in minimum 100 quantities for many items.. it's a huge down but it's the only place to get some of this stuff.

Yep, their site is clunky, but you can find just about any specification and information pertaining to fasteners with some perseverance. They have been my go to source for several years.

I don't know if it depends on the moon phase or just luck of the draw, but I have been able to order small lots by calling direct and speaking to a rep......knock on wood.

[ducatiz]

I find it strange manufacturers are not using Dacromet coatings on fasteners and brackets.  Can't be that costly if it is on this complete trailer set  http://www.sturdybuiltonline.com/Kodiak-Trailer-Slip-on-Disc-Brake-Kit-Dacromet-Stainless-5-Bolt_p_764.html

MDMetric's retail on zinc coated is about $22/100 and for dacromet coated is about $25/100 (M8).  I imagine in giant quantity that plain zinc or cadmium coated is a lot cheaper per unit.

Also... built-in obsolescence.

waitaminit... dacromet coated rotors and brackets?  DO WANT

[Howie]

Still got a VW?  Similar product, also used on fasteners  http://www.ecstuning.com/Volkswagen-Golf_VI--TDI/Braking/Rotors/ES2167531  Better?  Worse?  Dunno.

[ducatiz]

Still got a VW?  Similar product, also used on fasteners  http://www.ecstuning.com/Volkswagen-Golf_VI--TDI/Braking/Rotors/ES2167531  Better?  Worse?  Dunno.

Yup.,  Crashed the 2005 Golf TDI and bought a 2010 Jetta TDI.  Love them.

I'm interested, but dacromet is not a friction surface coating, so it should only be on the carriers but who knows?

[ducFrank]

What about titanium rather than steel?