Stainless steel properties

[jonathan]

Hi all,

Could somebody point to a website site giving the mechanical properties of stainless steel, 316 grade in particular ?

Or else just post it here. I'm having trouble finding trustworthy info...

Thanks !

[jehardiman]

What form? heat? pre-post work? There are many different cases.

[jonathan]

Hehe, that's probably what the problem is, actually... It's for threaded rods, but I don't really know what else to tell you... Are there really so many ? Maybe it would be easier to choose the stuff I need from a list of the different 316L's available...

Anyway, thanks for the reply, I hope you can give me some info

[Eric Sponberg]

Anyone designing and engineering boats should get a couple of good engineering handbooks, one of which is "Mark's Standard Handbook for Mechanical Engineers," published by McGraw Hill. A new edition comes out every few years. It has loads of engineering information, including the mechanical properties of many materials.

For 316 stainless steel, the yield strength is 30,000 PSI, the ultimate strength is 80,000 PSI. Modulus of elasticity is 29.5 million PSI. For 316L stainless, yield is 42,000 PSI, ultimate is 81,000 PSI. Modulus is the same.

Eric

[jonathan]

Thanks Eric ! We have some pretty good books in the office, but I was back home at the time of the original post... I knew it would be faster to ask here than go back for one

[jehardiman]

Hey Eric, those values are for hot finished bar stock and are not correct for threaded products.

ASTM F 593 lists all the heats which can range from 20 ksi yield @ 40% elongation to 95 ksi @ 12%. For the generic "chuck the bar in the threading machine" the properities (CW1,CW2) are approximately as show below:

1/4-5/8: tensile 100-150 ksi, yield 65 min, elongation min 20% in 4D
3/4-1 1/2:tensile 85-140 ksi, yield 45 min, elongation min 25% in 4D

If you have the head markings I can tell you exactly what it is.

[Eric Sponberg]

Correct, the numbers I quoted were for bar stock. It is very common in boatbuilding to order threaded bars for keel bolts, for example, since they are bent to an "L" shape at one end (end in the casting) and threaded at the upper end. They are made from bar stock and typically are not mass-produced products. Bolts with head markings meet minimum ASTM strength requirements, as you point out.

Eric

[jehardiman]

Yeah, but when you run the threads you work harden the material as well as well as decrease it's corrosion resistance, and when you heat it in a keel pour you decrease its properties. We make alot of specialized fasteners here in the shipyard and I have had to design them to ensure strength after post-fabrication. You can really mess up the temper and corrosion resistance of the nickel-chrome alloys like 316 by improper heating. In fact, I just checked and 316 is specificly restricted against hot working between 700 and 1700 F and that annealing is required to maintain corrosion resistance.

[grob]

For future reference, the best online source of material data is in my opinion

www.matweb.com

Gareth

[jonathan]

Wow, that is incredible! Why doesn't google return anything like that? Thanks grob, and all!