Hi all,
As part of a beautification project  on my Silver K75 I'm looking at replacing my steel connectors
with stainless steel. I've seen comments that the stainless should not be torqued as high as
steel. Not sure why. I just replaced the frame to tranny bolts (10mm) and made an error not
checking what is recommended for steel and possibly torqued them too high. Now my understanding
is that the torque is applied to keep the screws from backing out. As well as in say engine
applications to hold parts together. So I'd appreciate your comments or suggestions
as what should be the appropriate torques for stainless. Here is a table of
generic torque settings based on connector size. But note my read is this are for bolts only and
I'm wondering about such things other than machine bolts as well. Appreciate your
checking it. And of course there may be distinctions in the quality of stainless connectors.
 
GENERIC TORQUE SPECIFICATIONS (assumed steel)
Thread diameter N*m             ft.-lbs
5mm             3.4-4.9         30-43 in.-lb
6mm             5.9-7.8         52-69 in.-lbs
8mm             14-19           10.0-13.5
10mm            25-39           19-25
12mm            44-61           33-45
14mm            73-98           54-72
16mm            115-155         83-115
18mm            165-225         125-165
20mm            225-325         165-240

Here is Fastenal's guide to stainless fastener torque.  Their recommendation for lubed threads is in line with the top of the spec given in the Clymer manual for fasteners.  Since the fasteners in your kit are A2 metric the table is valid for your use.

https://www.fastenal.com/content/feds/pdf/Torque%20of%20Metric%20Stainless%20Steel.pdf

With the exception of some of the hardened bolts in the engine and steering head, I suspect that most of the fasteners that you are replacing are not highly stressed because a lot of them are threaded into aluminum.  There is more danger of stripping out the hole than in breaking the fastener.

The major problem with stainless is galling when fasteners are installed in steel without lube.  Lube them up and tighten to the low end of the spec and you should be okay.  I have been doing that on my bikes now with Harbor Freight torque wrenches for going on 8 years, and not had any problems with stripping threads or broken fasteners.

Thanks, Just what I wanted.

Also (and I realise I'm probably teaching granny to suck eggs) but don't forget the copaslip (copper grease) when installing stainless into ally. Dry stainless in ally will cause electrolytic corrosion i.e. the bolt will either never come out or will come out complete with what remains of the ally thread.

Dai wrote:Also (and I realise I'm probably teaching granny to suck eggs) but don't forget the copaslip (copper grease) when installing stainless into ally. Dry stainless in ally will cause electrolytic corrosion i.e. the bolt will either never come out or will come out complete with what remains of the ally thread.

Thanks, it never hurts to remind me. Though I use a product called Permatex (manufacturer) anti-seize. Suspect that's just an American trade name and it's probably all the same. I did put a dab on the end and across the threads. I'll find out if it's enough when I try to take it off.

The Permatex is good.  Been using it for years with good results.  The stuff from NAPA is good too.  Just make sure it has the copper.

Point-Seven-five wrote:The Permatex is good.  Been using it for years with good results.  The stuff from NAPA is good too.  Just make sure it has the copper.

Not sure if it has copper. Color is silver/grey ? But it's Permatex and so I assume it's correct.

If it's that colour then it's most likely aluminium anti-seize (allyslip!). The major difference is that allyslip doesn't have the same high temperature tolerance that copaslip does.

Dai wrote:If it's that colour then it's most likely aluminium anti-seize (allyslip!). The major difference is that allyslip doesn't have the same high temperature tolerance that copaslip does.

Ahhh, so the copaslip is only important for the exhaust studs!

Point-Seven-five wrote:

Dai wrote:If it's that colour then it's most likely aluminium anti-seize (allyslip!). The major difference is that allyslip doesn't have the same high temperature tolerance that copaslip does.

Ahhh, so the copaslip is only important for the exhaust studs!

Uh, Oh, I've never touched those!

jjefferies wrote:

Point-Seven-five wrote:The Permatex is good.  Been using it for years with good results.  The stuff from NAPA is good too.  Just make sure it has the copper.

Not sure if it has copper. Color is silver/grey ? But it's Permatex and so I assume it's correct.

Dai wrote:If it's that colour then it's most likely aluminium anti-seize (allyslip!). The major difference is that allyslip doesn't have the same high temperature tolerance that copaslip does.

The Permatex anti-sieze 80071/80078 is a blend of aluminum, copper and graphite. It has a high temperature range of 1600ºF, according to the manufacturer. How high are you shooting for? Which Permatex do have, j?