Shackle material to resist stress corrosion cracking

[jaydigs]

We use a safety cable and shackle system as a redundant backup for things we attach to ceilings/roof structures. For the applications going into indoor swimming pools we have specified mostly 6%Mo fastener material to guard against SCC. I'm having trouble finding a shackle made of this material however. I had heard about some coatings with extremely high salt spray ratings and wondered if a 316 steel with some treatment might not work? Does anyone have any thoughts on this?

Thanks

 

[TVP]

Unless the quantities needed are large, I would have shackles machined from a suitably resistant stainless steel, e.g., 6%Mo. Most of these high performance coatings that you have reviewed are meant to be applied over conventional carbon/alloy steels that have been pretreated with zinc phosphate or electrodeposited zinc/zinc alloy coatings. Surface preparation of Type 316 would be a big question mark for me.

 

[metengr]

You can also evaluate the use of a duplex stainless steel for shackles.

 

[Compositepro]

I would guess that sailboat hardware might work well.

 

[EdStainless]

No, boat hardware isn't rated for overhead safety.
You would be better off with 2205. It isn't as corrosion resistant as a 6% Mo, but is stronger and resists cracking better.

= = = = = = = = = = = = = = = = = = = =
Plymouth Tube

 

[MJCronin]

Ti ?

http://www.berkeleypoint.com/products/titanium/longdshackle.html

-MJC