Use of Stainless Steel AN bolts in place of CAD plated AN bolts

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braywood
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Joined: Fri Feb 19, 2010 11:12 pm

Use of Stainless Steel AN bolts in place of CAD plated AN bolts

Post by braywood » Sun Oct 04, 2020 8:05 pm

I would like to use SS AN bolts in place of CAD plated bolts for all fitting attachment on a Pietenpol Air Camper. Is there any problem? If so what would be the issue?
Mark Bowler
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Mark A
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Re: Use of Stainless Steel AN bolts in place of CAD plated AN bolts

Post by Mark A » Mon Oct 05, 2020 12:10 pm

Stainless bolts are more prone to galvanic corrosion in contact with aluminium than Cadmium plated ones.
The bolts won't corrode but the adjoining metalwork is at risk unless a suitable galvanic barrier is used.
Mark Albery
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braywood
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Re: Use of Stainless Steel AN bolts in place of CAD plated AN bolts

Post by braywood » Mon Oct 05, 2020 12:40 pm

Hello Mark - I'm making my fittings of titanium (don't ask) so no issue with aluminium. I want to know how the SS AN bolts compare strength wise to the CAD plated bolts. According to the LAS (ACS) site hardware listing, both meet the minimum tensile limit of 125ksi. Yes SS is not as strong, but both meet the minimum spec.
Mark Bowler
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Bill McCarthy
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Re: Use of Stainless Steel AN bolts in place of CAD plated AN bolts

Post by Bill McCarthy » Wed Oct 07, 2020 7:38 am

Stainless steel is subject to stress corrosion cracking. Stress arising in its duty and in the manufacturing process.
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Mark A
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Re: Use of Stainless Steel AN bolts in place of CAD plated AN bolts

Post by Mark A » Wed Oct 07, 2020 1:59 pm

With Titanium/stainless the stainless will become the galvanic anode and subject to corrosion, the Titanium will be the cathode and not at risk, so you would still need a galvanic barrier.
I believe that they both meet the strength requirement of AN bolts, so that should not be an issue.
Mark Albery
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braywood
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Re: Use of Stainless Steel AN bolts in place of CAD plated AN bolts

Post by braywood » Wed Oct 07, 2020 3:41 pm

Thanks Mark - everyone seems to think SS is like jello - no strength at all.
I understand about the galvanic issue - would you think CAD plated AN hardware would be better than SS? There are issues with cadmium/titanium as well. I thought the SS hardware would be less of an issue.

Mark
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tnowak
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Re: Use of Stainless Steel AN bolts in place of CAD plated AN bolts

Post by tnowak » Thu Oct 08, 2020 8:20 am

Mark,

I think this is a question you should be asking LAA Engineering about.
They will be able to advise if use of SS bolts in your particular application is acceptable.

Tony
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terryws
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Re: Use of Stainless Steel AN bolts in place of CAD plated AN bolts

Post by terryws » Mon Nov 23, 2020 7:10 pm

Hi Guys

There are many grades of stainless steel, with differing strengths, machining characteristics, welding characteristics and corrosion resistance. Some are magnetic, some are not. Here is a link to one source of information, and there are many others on the internet

https://continentalsteel.com/stainless-steel/grades/

The two common grades are A2 (304) and A4 (316) and they are VERY different to work with.

I hope this helps

Terry Slater
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Terry Slater
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