marine grade stainless steel 318? 316?

[two stroke mick]

I am hoping to get an A frame constructed in the next fex weeks. What is marine grade stainless steel called 318? or 316?

[Hightower]

316

[RIVA]

316? make sure which one. carbon content changes, and something else as well.

You will get less t stain
http://www.engineeringtoolbox.com/st...rds-d_445.html

[BruceB]

The normal grades for marine use are 304L or 316L. Usually 316L for non submerged purposes like A frames.

[martini]

304L is for kitchen utensils. 316L is for marine applications but no stainless is suitable for use below the waterline

[Jimmy C]

has anyone used or able to reccommend a fabricator for an a-frame in or around Southampton?

I think there was guy on here offering his services, but can't find his number

Cheers

Jimmy
--------------------------------------------
Found the post----- http://rib.net/forum/showthread.php?...ght=mark+frame

Havn't taken him up on the offer yet.... but sounds good.

[BruceB]

304L is normally sold as food safe grade but you get crevasse corrosion on 316L in permanently submerged applications which is why AFAIR 304L is used. It all comes down to application and conditions. We used to use both grades on kit down to 6000m deep. 316L was not good for de-oxygenated conditions and 304L handled it better. We also used Aluminium alloys but they had to be heavily protected by anodes.
You can use stainless below the waterline, it just depends on the conditions and what it is for. For a Rib that is not kept in the water permanentely SS materials are fine and I have used them successfully for some years but the water is very oxygenated at the surface. For permanently submerged condition like yachts and moored RIBs I would probably go for Bronze fittings.
For any above surface application I would 316L.

[Richard B]

Originally Posted by Jimmy C

Found the post----- http://rib.net/forum/showthread.php?...ght=mark+frame

Havn't taken him up on the offer yet.... but sounds good.

Chubby sounds good at that price!

Failing that, try http://www.stainless-steve.co.uk/ or my mate Gordon can do any fabrication from A-frames to a full pontoon and gantry. He's based in Southampton.

[Jono]

Originally Posted by martini

304L is for kitchen utensils. 316L is for marine applications but no stainless is suitable for use below the waterline

Utter bollox....

[iandl]

Originally Posted by martini

304L is for kitchen utensils. 316L is for marine applications but no stainless is suitable for use below the waterline

316 was the prefered we used .....industrial washing machines being loaded with alsorts of chemicals, salts and acids didnt seem to mind being submerged......i have repaired one still with original drums from the 60's .....

I