Duplex 2205 SS for Chainplates

[laika]

I'm looking at ordering a sheet of 2205 from McMaster Carr to replace the chainplates on my boat: McMaster-Carr

I plan on having a reputable machinist cut and drill for me, using the old plates as templates. My twin backstays will need a slight bend, but despite 2205 having a lower ductility, don't foresee any issue there. Say 15% bend.

I've read through a lot of literature and forum posts on the topic and, other than than the cost, 2205 seems like the perfect material. However, it is more magnetic than 316L and this is the last real question I have. Might using a highly-magnetic SS for chainplates present a problem down the road?

I plan on using standard 316 bolts in conjunction with the 2205.

[neilpride]

Anything far more durable in terms of corrosion resistance and strenght than 316 ss its worth the effort, magnetic or not, i dont see any problem so far and i guess duplex 2205 is a step forward, hell no idea why this days we are still using 316ss in boats.... my favorite material could be titanium but the price is kind hummmm, not yet....

[Jim Cate]

Laika, our chainplates are fabbed from 2205. They are now 24 years old. Last year I had the mast out, and pulled the chainplates for inspection. They were pristine... no corrosion of any sort. They are indeed quite magnetic, but so what? Don't mount your compass next to them!

Cheers,

Jim

[Stumble]

I would really recommend going with Grade 5 titanium over stainless. Even in the duplex stuff nothing has the strength or corrosion resistance of G5, and the price frankly becomes a non-issue at this point.

[laika]

Thanks for the feedback. And Jim, duly noted..I'll be sure to check myself before being irresistibly drawn to remount the compass near those shiny new chainplates

I'm still not totally set against Ti, though I think either 2205 or Ti would both be more than sufficient for the job. I understand the galvonic corrosion issue between dissimilar metals is a non-issue between Ti and 316.

Greg, Allied Titanium uses Ti manufactured in the USA, correct, and gets it from a reputable stock? ie not cheap stuff welded together from scraps