Stainless Steel Tubing

[Ian_Rob]

I am after some 25mm dia stainless steel tubing and pre-formed bends that I can weld up to make a small alteration/addition to my cockpit railings. What is the normal spec? Is it 316 or 316L, typically 1.5mm or 2mm and any suggestions where I might get the best price?

 

[PCUK]

304 is fine 316 only needed below waterline. Bends and elbows on Ebay.

 

[mucklestone]

Haven't got any experience welding stainless, but 304 bolts certain rust if they get salty spray on them.

 

[PCUK]

Haven't got any experience welding stainless, but 304 bolts certain rust if they get salty spray on them.

So does 316 if never cleaned. Anyway we are talking about tube here!

 

[vyv_cox]

Welded stainless steel, whether 304 or 316, should be L (for low carbon) if corrosion is likely.

 

[gordmac]

Welding can lead to the area round the weld ceasing to be stainless!

 

[vyv_cox]

Welding can lead to the area round the weld ceasing to be stainless!

Not if the L grade is selected. When the standard grades are welded some of the chromium forms carbides, which as you say, reduces chromium locally and causes the HAZ to be susceptible to corrosion . The L grades have lower carbon and contain strong carbide formers such as niobium, thus the chromium remains in the base alloy.

 

[Ian_Rob]

L grade it is! Thank you.

 

[Halo]

Am important point on marine applications is to thoroughly polish the job when you have finished. If you can then apply or soak in acid and then rinse off before polishing. Both these procedures will help passivate the stainless and increase corrosion resistance.

 

[PCUK]

Very good point!

 

[sparkie]

I am after some 25mm dia stainless steel tubing and pre-formed bends that I can weld up to make a small alteration/addition to my cockpit railings. What is the normal spec? Is it 316 or 316L, typically 1.5mm or 2mm and any suggestions where I might get the best price?

Several stockists on Ebay.