301 Full Hard Stainless Steel Question 2

[011235813]

I've been getting some 301 Full Hard in from my supplier. The data sheet calls out a minimum Rockwell Hardness of C41, however my in-house testing shows a Knoop Hardness of 550, this translates in to a Rockwell of ~51. Quite a bit more than the minimum spec (Tensile strength of ~1790Mpa vs 1276Mpa), I'm wondering if anyone has experience with 301 full hard... would you say it is normal to see hardness that far above the minimum or can I expect to one day get some material in that will have a much lower hardness?

Thanks.

 

[mcguire]

301 full hard can be all over the board as long as it's above the minimum. This item is an outlet for material which has been disqualified for more narrow specs, such as 3/4 hard which turned out too hard or heavily cold rolled 301 which missed gauge. Thus, this item is unfortunately an outlet for mill rejects. Therefore unless it's made to your order of restrictive specifications, don't expect consistency.

Michael McGuire

http://stainlesssteelforengineers.blogspot.com/

 

[EdStainless]

If you want (need) consistency then order to a specified strength range.
A666 has no hardness listed at all. Tensile strength, yield, elongation, and bend testing are what are used to specify the degree of cold work.
If your stuff meets the elongation and bend test requirements then it is within spec.

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