Stainless Steel Tool Wrap

CDHumiston

CDHumiston

Well-Known Member
For those of you who do your own heat treating do you use 309 or 321 tool wrap?

I was using the more expensive 309 that is rated to 2250 degrees because it was all that was in stock when I ordered.

The less expensive 321 that is rated to 2000 degrees is available now. I don't heat anything over 1950 degrees.

What is the consensus on using the 321 instead of the 309?
 
As I understand things, the 321 is rated to 2000 degF and is pretty reliable to 2000 degF. Above that, the 309 is significantly more reliable.

If you never go above 2000 degF, there is no technical benefit to using the 309. There are certainly those who use it for everything, but this is usually for non-technical (though entirely valid) reasons. In your case, the reason was availability. For some it will be to eliminate the possibility of using the wrong foil on a blade that needs over 2000 degF.

In your shoes, I'd buy the 321 and clearly mark any remaining 309 so that you have it if you ever use a steel that needs over 2000 degC. As a broad oversimplification, it tends to be more expensive steels that need the higher temperatures. Needing to buy expensive steel and expensive foil for a first foray into something more exotic than you are used to might not be easy to justify. "Just" buying the steel and using the foil that you already have might be easier.

I usually try to explain things in terms of clothing and shoes when talking to She-Who-Must-Be-Tolerated: In this case, it's analogous to a "new dress and new shoes" vs a "new dress to go with the shoes she's already got" argument.
 
CD,I've used 321 for years with no issues going up to 1975, I highly recommend dusting your knives with talc to help prevent the wrap welding to the blade. I had that happen a couple times years ago and it makes a real mess to the blade.
 
Thanks guys, I appreciate the feedback. I'm going to give the 321 a shot. I still have some 309 for higher temp steels. I noticed the thickness of both 309 and 321 is the same. The 329 must break down at higher temps. That may be the reason it sticks to the steel.

I guess plain talcum powder will work?
 
I use the 309 but strictly for Stainless Steels. I felt the 321 for the SS was marginal because of the SS's higher temperature to harden. The 309 gave me a bit of wiggle room I felt.
 
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