J.S. performance testing results

[kbaknife]

OK, I truly don’t want to get long-winded here, but it’s important to me to explain a few things!
First, I want to thank Don Hanson for putting up with me for the last few weeks, and for the corned beef sandwich!
I’m truly honored to be first J.S. “Testee”!
Thanks, Don.
Secondly, this knife performed SO WELL, I really need to say a few words about the people who helped me put together my current heat-treating “package”.
Jerry Rados has a knife “philosophy” that was quite something for me to run into as a beginning knife maker. Talk about “over my head”! I jumped right into the deep water at the beginning, now 9 years ago.
I went to Willow Bow a few years ago and got indoctrinated by Ed Fowler and the Willow Bow Gang and I brought back forging, post-forging, and grinding techniques that I use every time I make a knife.
Having been to Ashokan twice now, and an in-frequent “bother” to Kevin Cashen, I’ve utilized his metallurgical expertise to the maximum of my understanding.
(When’s the last time you saw Ed Fowler and Kevin Cashen in the same topic??!!)
I have used Jim Siska’s take-down assembly method exclusively for the last two years at his approval.
Anyway, these guys, along with inspiration from everything Bailey Bradshaw does, has helped me get to this point.
My contact with those fine gentlemen helped me put together two knives that were darned near indestructible.
What can I say – razor-xxxxxxxx sharp.
Cut like a champ.
Chopped like another champ with absolutely no damage, chipping, bending, and remained razor sharp.
Then, the part that I liked the most!
On my home-test-knife, I was amazed that it performed so well, but mostly, that when it came time to bend the blade, I couldn’t even insult it! I only weigh 170 pounds, but I had my legs wrapped around the work bench, and still could hardly bend the knife.
Then, I put a 3 foot cheater bar on the handle, and bent it waaaaaaaay past 90 degrees. I never heard a crack! I kept waiting for a crack! Nothing. And, it went back to under 20 degrees from straight!
I thought it was a fluke.
Then, with my official test knife at Don’s, the same thing happened! I could BARELY get the blade past, maybe 30 degrees by hand.
So, I used the cheater again.
No crack, not even at the fine cutting edge, and this one returned to exactly 20 degrees from straight.
Both knives cut - well -, stayed razor sharp through abuse, and defied destruction.
So many times I have seen test knives that had this sharp “kink” right at the vise jaws, cracked

[fat pete]

Thats cool....I appreciate you posting the test.....and also good Job!! I hope I can do this sometime....

[Don A]

Great report. Congratulations.

How 'bout a quick run-down on the particulars?

Steel type, heat-treat, etc.?

Don

[kbaknife]

OK, let's see.
They were both forged from 5160, but NOT bar stock. My steel is in 20 foot lengths, 1" square, and made back in '84.
Part of Ed Fowler's knifemaking philosophy involves forging from large stock, which is one of the reasons I went to Wyoming and took his seminar a few years ago.
The repeated and numerous thermal cycles that take place when forging from larger stock, seemed to give him better performance, and I am inclined to agree.
Also included are three post-forging quenches to refine grain, followed by three reducing heat normalizing cycles.
This is followed by a digitaly controlled oven and a controlled sub-critical anneal process that takes just under 13 hours.
After the blade is convex ground, it is held at 1525 degrees for 18 minutes and edge quenched.
Then, three 350 degree temper cycles.
All pretty basic stuff, but if you REALLY control the basics every time, you should get a blade meant for performance.

[cdent]

Hi Karl,
Do you do any normalizing after the grinding?

Any comments on how you arrived at the long soak for your quench?

Is the sub-critical anneal your ideal set up to quench?

Sorry for all the newbie questions, your process is fascinating to me.

Take care, Craig

[kbaknife]

I do no normalizing after grinding. I had already done three post-forging quenches to refine grain, and then followed that with three normalizing cycles, which have the tendancy to refine grain as well.
The finer the grain, the less hardenability!
I'm not going to stack three more on top of what I've already done.
20-25 minutes is even MORE acceptable for a soak time than what I do.
The alloy content of 5160 - especially the chromium - requires this soak time.
Held at 1525, there is no problem.
Simpler steels like 1084, 1095, W1, can be brought up to only about 1480 and held for only a few minutes.
After the spherodizing anneal that I do for easy grinding and drilling purposes, the carbides are all "pooled" up in little clumps. The soak time helps to break these carbides up and return them to "solution", making for good hardening.
This sub-critical anneal is an industry standard for 5160:
hold at 1375 for 2 hours.
Cool quickly to 1300.
Drop to 1200 degress @ 10 degrees per hour.
This gets EVERYTHING all evened out after the stress it goes through during forging and sets it up for a really even hardening.

[Pault17]

holy heck!! that just about blows any ideas I had of just quenching in a bucket of used motor oil right out the window:o

OTOH, I know that I am not anywhere near ready to even pretend any knife-making attemp. Beautiful work and thanks for the explanations.

[cdent]

Thanks Karl for taking the time and having the willingness to share. Lots of great food for thought. Can't wait to hear how you handle your MS test knife.

Take care, Craig