Stainless Steel Grades Specification

[gmoney731]

Hello,

I am working on a minor structural rehabilitation project, that will utilize some structural steel. I am not concerned with the capacity of the steel...I am spec-ing stainless simply to prevent corrosion. I am editing 05 50 13 (Misc. Metal Fabrications), and 05 50 14 (Structural Metal Fabrications) from UFGS.

We did this same upgrade at a different, but similar project, and painted it as opposed to spec-ing stainless steel. For one reason or another, the paint was not enough to prevent the steel from rusting. This time around, I want to spec appropriate stainless steel grades for shapes, connections (studs and high strength bolts), etc. However, I've never used stainless steel before, so I could use some guidance in spec-ing the following grades:

Stainless Steel Shapes

Structural Tubing

Steel Pipes

Fittings for Steel Pipe

Plates

Anchor Bolts

I have read the AISC Design Guide, but it wasn't apparent to me which "grade" to spec. Thanks for your advice and guidance.

 

[jerseyshore]

304 and 316 are most common. I usually only specify bolts and hardware but I assume beams are spec'd the same way. I do remember that the table in that design guide does list what grades are used for each type of member but I'll let someone else answer which ones are best.

 

[phuduhudu]

You can't just substitute stainless steel for carbon steel as it has different properties both for modulus and strength properties. It is designed using different codes here in the UK. If you really aren't worried about mechanical properties at all then you should check with suppliers what grades they supply so you don't end up specifying something that can't be sourced.

 

[EdStainless]

There is a design guide from AISC titled Structural Stainless Steel (I believe that it is #27).
In some places there is a good supply of SS structural material.

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P.E. Metallurgy, consulting work welcomed

 

[JLNJ]

AISC just revised the stainless specification in 2021 and updated DG #27 at the same time.

304 stainless is a little odd in that the yield strength is relatively low (around 30 ksi) but the ultimate strength is more than double that, likely higher than the ultimate of grade-50 ASTM A992. You also will need to pay special attention to the fasteners. We get used to high-strength bolts for steel connections, but you need to carefully specify stainless bolts if you want them to be high strength similar to the old A325.

 

[EdStainless]

In Europe they are tending to use a lot of lean duplex SS for structurals.
This stuff is usually 65ksi min yield and depending on the grade 95-105ksi UTS.
It has about the same corrosion resistance as 316 and slightly lower thermal expansion.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed