Question regarding 304 and 301 stainless

[Myndex]

Hello,

I'm working on a lounge chair design, and the client wants to use stainless steel for the frame elements, as they like the appearance. However, they also want the elements very thin (again for appearance).

My question relates to spring tempering 301 or 304 stainless barstock. The design calls for a bar that is either 3/8" or 1/2" thick x 1 3/4" wide and approximately 3' in length, with the main load at the mid point, perpendicular to the wide surface of the bar.

To accomodate the dynamic load of a 300 pound person plopping themselves down on the seat, the FEA I ran indicates a deflection of approximately 1.5 to as much as 2.5 inches at the center. See attached AVI animation for details.


MY QUESTION: It seems to me that there's too much deflection, and that 304 would permenantly deform here. I'm unclear on theissue of spring tempering austenitic stainless. From reading several data sheets, it seems that 301 would be preferred here, though it doesn't seem as readilly available in the bar form needed.

So, can 304 be tempered to allow this amount of displacement without permenant deformation?


Thank you for any comments on this topic.

Andy




Andy Somers
Myndex Technologies Inc.

 

[Goahead]

Hello,
The following source is specialized in springs:

http://www.smt.sandvik.com/sandvik/...eb2c5f873de6dcaa41256567005a9819!OpenDocument

They may be able to help you finding what you need.
If the thickness does not meet your requirements,you can build a leaf spring in layers.

No thermal treatement will improve 304 strength.
Stay away from welding.

http://www.welding-advisers.com/

 

[Robertmet]

The 300 series cannot be heat treated to harden. It can only be cold worked to harden.Of that series 301 will cold work quicker.I've used 301 springs but nothing that thick.

 

[mcguire]

You can get whatever strength you need, 1/4 hard, 1/2 hard, etc., in 304 as well as in 301.

Michael McGuire

http://stainlesssteelforengineers.blogspot.com/