Help in Understanding the Stronger Grades of 304 Stainless Steel
Help in Understanding the Stronger Grades of 304 Stainless Steel
(OP)
We're looking into using a higher grade of 304 stainless steel tubing than the standard grade. My question is about the 1/8 hard, 1/4 hard, etc. grades. They have the desired yeild strength (60-75 ksi) but is the yield strength constant, or consistent throughout the thickness or is the increase in strength just a surface characteristic?
Thanks,
Dave
Thanks,
Dave





RE: Help in Understanding the Stronger Grades of 304 Stainless Steel
RE: Help in Understanding the Stronger Grades of 304 Stainless Steel
Commonly work hardened SS is available as sheet (strip), wire, and tube. The Old 1/8 and 1/4 hard only applies to sheet. There are wire specs of their own, and tube is all custom specified.
In tube we don't see any property issues with 1.385" od x 0.208" wall. We have turned samples to half of the wall and the tensile is almost the same.
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Plymouth Tube
RE: Help in Understanding the Stronger Grades of 304 Stainless Steel
For those interested, here's a little background on the situation: The part is a band about 2 inches long with an ID of 4 inches and OD of 4.2 inchs (both dims are nominal). We will be making circumferential grooves in the band's outer surface. These grooves have constant width of .25 inches and are about .05 inches deep. They're rounded on each end. It's precisely these cuts that I'm concerned about.
I've done a finite-element analysis which shows that I'll have von Mises stresses of about 30 ksi in the majority of the band and about 50 ksi in the bases of the grooves (the bases of the grooves are flat and .25 inch wide). Hence the reason for considering the hardened version of 304.
Question: The reference trade book that I have only shows "1/8 hard 304," so I appreciate your remark Ed about that being "old" - and I thought the book was current :). So, what is the current grade of hardened 304 that I should consider - is it "full hard?"
Thanks, Dave
RE: Help in Understanding the Stronger Grades of 304 Stainless Steel
If you had material with a minimum yield strength of about 80ksi or so you should be alright. Don't go any stronger than you need to. The ductility of SS is what gives you the toughness.
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Plymouth Tube
RE: Help in Understanding the Stronger Grades of 304 Stainless Steel
RE: Help in Understanding the Stronger Grades of 304 Stainless Steel
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Plymouth Tube