Paul Deslandes Posted February 26, 2008 Share Posted February 26, 2008 A friend of mine is installing a new and unusual engine in a 7 and is having to fabricate new mounting brackets. He's considering using stainless steel because its stronger than mild steel and could be made at approx 25% of the weight. However he's concerned, and I am too, that the stainless will be brittle and would be more likely to crack whereas mild steel would be more forgiving of vibration. The engine block is cast aluminium so there may also be a corrosion consideration. Any metallurgists/mechanical engineers out there with an informed opinion? and/or experience? Edited by - paul deslandes on 2 Mar 2008 20:01:09 Link to comment Share on other sites More sharing options...
Foxy Smith Posted February 27, 2008 Share Posted February 27, 2008 Stainless steel work hardens after relatively few flexing cycles this leads to embrittlement and cracking surprisingly fast. Any theoretical weight saving you'ld lose by having to increase the section of the stainless to try to prevent flexing and cracking. This is not a job for stainless steel in my opinion. Link to comment Share on other sites More sharing options...
Sheds Moderator Posted February 27, 2008 Share Posted February 27, 2008 Have a word with a steel manufacturer re your application. Not all stainless is brittle. Not all stainless is the same, of course. Amongst the "18/8" types, standard stuff is 304, used in general fabrication and with low brightness and reasonable corrosion resistance. 316 and 316L are the food/chemical industry favourites, with increased corrosion resistance in the presence of chlorine compounds as a result of, er, molybdenum addition, IIRC. Cutlery steel has a high chromium content to give the shine, but it's expensive and structurally poor. Gawd knows what they put in surgical stainless to keep an edge, a shine and corrosion resistance. You know, it's almost as if there's a whole industry devoted to it... If you really want to go for it, try titanium! Link to comment Share on other sites More sharing options...
Paul Deslandes Posted March 2, 2008 Author Share Posted March 2, 2008 Thanks for the feedback. He's abandoned the idea of using stainless and is going for mild or carbon steel. Given that there's a potential problem (ho ho) with an ali block and dissimilar metals, should the mounting bracket bolts be plain steel or plated? I think zinc plated will lose their plating pretty quickly so I am thinking self coloured. Link to comment Share on other sites More sharing options...
Sheds Moderator Posted March 2, 2008 Share Posted March 2, 2008 Just paint it. No bimetallic issues then. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now