Stainless steel bolts

Andy Leeds UK

OK, I'm fed up with all those BMW bolts that are made out of a mixture or half oxidised iron and cream cheese. So, I thought I'd go stainless on the engine bars, luggage mounts etc. However, despite holding an engineering degree (I was going to get medicine but the colour photocopier was bust) I am struggling to work out the relative strengths and preparation required. What I have worked out so far:

R rated steel bolts have a tensile strength of 45 tons per inch square or 620 MPA.

Titanium is rated at 895 MPA

A4 stainless is at 700 N/mm2 or 686 MPA.

Did I get this right?

Also, there seems to be contradictions about using copper slip and not using copper slip on stainless.

As someone who honestly though cold welding was done in Siberia by a man called Boris with a blow torch, I'd apreciate any pointers/practical experience.


Dont ask me about stainless steel bolts - I'm completely nuts!!!!:D :D :D
Andy Leeds UK said:

A4 stainless is at 700 N/mm2 or 686 MPA.

Did I get this right?

Who knows?

But the angle of dangle
equals the radius of the anus
times the throb of the knob!

:D :D :D

Re: Re: Stainless steel bolts

Greg Masters said:

But the angle of dangle
equals the radius of the anus
times the throb of the knob!

The ****ing editorial police must be off-duty today!

back to the stainless....
I replaced most of the fasteners on my FJ with stainless and just ordered a workshop bargain pack of assorted A2 stainless M6 socket capscrews to start the replacement process on my GS from Stig Fasteners
who note "You are also cautioned that stainless steel is not as strong as high-tensile steel, and should not be used to replace caliper bolts and other stressed components. If in doubt, check with manufacturer".
NB A4 is a marine grade and available from chandlers.


PS I'll post the various sizes I come across - if others do we can build up a complete inventory of required sizes.
In a former life as a marine engineer, I vaguely recall that using stainless into aluminium using copper slip can cause corrosion problems. Dissimilar metals and all that. Probably better to use high melting point grease.
But even I don't trust my memory, so why should you. Intrigued now so will read up.
Used to be a firm in Belfast called Swift Screw Products Ltd, advertising slogan: 'Nothing Beats a Swift Screw'. Never could figure out if they were either naive or just taking the p!ss
It's quite simple. I've got a spirit level in brick laying, and this is the formuli I use. Get nice shiny brainless steel bolt, remove bolt you wish to replace, and bung the brainless one in it's place, Horse it up as tight as you can (if it strips the thread, this is simply engineering way of saying you're a complete **** and you shouldn't be allowed near anything mechanical ever) As for the tensile strenth of bolts for for brake applications, who really gives a toss. I found the stainless bolts that are holding my calipers on, and they've been there for the last 116000 miles, and they were still there when I pulled the brake on today. What more do you need to know. PS I bet you're in the BMW Moaners club
Andy Vernon said:
PS I bet you're in the BMW Moaners club

I'm mortally offended by this remark and challenge you to a pipe smoking duel!
Please wear appropriate slippers and bring at least an ounce of ready rubbed.

In my limited experience of stainless bolts the real problems seem to start when putting a stainless bolt into a stainless fitting (without any loobrication) then the bolts would seize up just by looking at them. Then the fun starts of trying to get them out, try lots of expensive cobalt drills.

If money is no object why not try using titanium bolts, reduces weight, doesn't readily corrode and doesn't look like your an escapee from the wing or BMW club.

BTW I haven't escaped from the BMW club, yet!
Thanks guys.

The plan at present is as follows:

1. Use stainless for stuff thats not going into the frame and use HT grease. eg Engine bars.
2. Use Titanium where its exposed and needs to be strong. eg sidecar frame bolts, F650 luggage frames.
3. Use black coated steel and lots of copper slip where you can't see them.

At least with all them dissimilar metals, when the bikes are just a stain on the garage floor, it'll be an interesting colour:D


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