Spyderco Forums

Title says it. What are your thoughts?

sal

62RC in a thin, light, rounded spine 8" chef knife.

I agree, 62RC+/-, it would be a waste if the steel was too soft to take a keen acute edge, and its not prone to massive chipping.

Run it up to the high 60's. 68-69. Push the steel a little.

Archimedes wrote:Run it up to the high 60's. 68-69. Push the steel a little.

Wouldn't that make it too brittle though? I almost think that 64--66 would be a better compromise.

In a folder or smallish fixed blade I'd say there are good reasons to try rc 61 ( rc 60-63). IMO, there is a lot of performance gained going from rc 58 up to rc 61. With this steel one needs a bit higher hardness to get the steel to really perform. Depending on how things are done it can go higher or lower and still have good performance but for me I'd go for the sweet spot when I could unless there was a reason not to.

If I needed higher hardness than rc 62 I'd probably try a different alloy.

Thanks for giving this serious consideration. It's one of my favorites and I tune in every time I see it being discussed.

Joe

Archimedes wrote:Run it up to the high 60's. 68-69. Push the steel a little.

It would take some pretty demanding cycles to get 69 HRC in 52100.

sal wrote:Title says it. What are your thoughts?

Don't use hardness as a means to judge how to harden steel.

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There are a few general ways to approach it based on what you are trying to achieve :

-If you want a balance of strength/toughness/wear resistance then soak just enough to put ~0.6% carbon in solution, leave most of the chromium undissolved, use an agitated oil quench to ensure minimal diffusion, cryogenics (if possible), to reduce retained austenite, and then temper ~350 F to 400F to get the plastic zone you want. Joe Calton has a video recently where he shows a very simple check you can do to estimate the start and extent of the plastic zone with very basic materials.

-If you want a very high toughness/durability then reduce the soak time a little, don't use cryogenics, and temper just in front of the 500F embrittlement zone. This will give a blade with a much wider plastic zone but a reduced strength and wear resistance.

-If you don't care much about toughness then soak a little hotter/longer, it is critical to use cryogenics as the retained austenite will be very high, and temper low, 325-350F. This gives the highest strength and wear resistance but you won't have much plastic deformation at all.

There are guys on HypeFree who have the exact cycles on each one of these and have described how they behave in terms of rope cut and flex and impact tests. Most people tend to do the first one because it tends to have decent performance over a broad range of tasks and users.

Ferris Wheels wrote:62RC in a thin, light, rounded spine 8" chef knife.

This would be fantastic. Even better if you pair it with a nice micarta handle a la the temperance two but polished.

On a more serious note I would vote just over 60. I have a couple of kitchen knives in this steel and they are fantastic.

A question I should have asked before giving an opinion: what type of blade do you have in mind?

Final slightly off topic comment, what about the kiwi 4 in this steel? Polished g10 and non ambidextrous wire deep carry pocket clip.

MS J Neilson who makes all my fixed blades out of 52100 just sent me a text 58-59. Same for MS Bill Burke and MS Ed fowler I believe don't quote me on that . Both Burke and Fowler have study 52100 for knife use more than anyone I bet .In practical application and scientific methods like metallurgy. Either MS Fowler Or Burke would be a great wealth of knowledge. I bet they would be more than happy to take your call Sal. If not I know J. would no problem he is a great guy easy going knows his business and does not mind sharing his knowledge and experience.

sal wrote:Title says it. What are your thoughts?

sal

Hi Sal,

I would have to ask optimal for what type of knife? :)

As optimal for a slicer would be much different than optimal for a chopper and both would be different than optimal for something in the middle as in all around use.

For a Kitchen knife that is thin I would say around 63-64 range.

For a Slicer, smaller fixed blade 4" to 5" or so something in the 62-64 range depending on exact geometry.

For a folder I would say 61-62 with more normal geometry, maybe slightly thinner than normal in the .015" range or so.

For larger fixed blades or choppers, hunting knives etc that will see harder use something around 58-61 max depending on what the knife is exactly.

All of that is taking into count the production process and not heat treating one or two knives at a time.

All of this is just my opinion based on what I have seen over time, geometry would have a large impact on what the final hardness ranges were as would the actual use based on the design of the knives.

The actual HT process is going to vary greatly depending on what the actual needs of the end product will be and how the testing goes to narrow it down. So without knowing what you have in mind I am just shooting from the hip at this point.

Jim

I have bluntcut's slicer @ 62-63 HRC. He knows his 52100. Meanest yet smoothest cutter and even shave (dry face stubble) with no irritation.

My hope is going up seeing this being asked :D

Don't push it ; 61-63 HRC is my bet.I hope for a FFG folder since not everyone need a chef knife or a fixed blade.But don't go beyond 63HRC.

62-63 for a folder. Optimizing for toughness given the purpose behind most of Spyderco's knives doesn't make much sense to me. I've seen this steel likened to AEB-L/14C28N (different steels but similar) and that steel is far better optimized at 62 rc vs 59-60 as far as a balance of toughness and edge retention IMO.

Thanx for the input. I told Annika to make them 62-63, but I thought to check with my "consultant steel junky's".

Thanx for the input Cliff. Our heat treater is a metallurgist. I'll share your info with him.

I plan to put it in a Millie Jim. Mostly because I wanted one in 52100 as a work knife on the mountain. I figured you and Joe would probably want one as well. So we have 3. We'll make 1000. It was a real PITA to find it rolled to the thickness wanted. It's also a bugger to work with in a production environment. Not too many production folders out there in 52100. I can see why.

sal

sal wrote:Thanx for the input. I told Annika to make them 62-63, but I thought to check with my "consultant steel junky's".

Thanx for the input Cliff. Our heat treater is a metallurgist. I'll share your info with him.

I plan to put it in a Millie Jim. Mostly because I wanted one in 52100 as a work knife on the mountain. I figured you and Joe would probably want one as well. So we have 3. We'll make 1000. It was a real PITA to find it rolled to the thickness wanted. It's also a bugger to work with in a production environment. Not too many production folders out there in 52100. I can see why.

sal

Hi Sal,

Yes, I figured it would be a PITA to work with due to various reasons. :D

Oh yeah, you have that pegged, I think Joe would love one and I would as well, love 52100 personally, that and A2. :cool:

Jim

sal wrote:Thanx for the input. I told Annika to make them 62-63, but I thought to check with my "consultant steel junky's".

Thanx for the input Cliff. Our heat treater is a metallurgist. I'll share your info with him.

I plan to put it in a Millie Jim. Mostly because I wanted one in 52100 as a work knife on the mountain. I figured you and Joe would probably want one as well. So we have 3. We'll make 1000. It was a real PITA to find it rolled to the thickness wanted. It's also a bugger to work with in a production environment. Not too many production folders out there in 52100. I can see why.

sal

Count me in Sal.So we are 4 and counting :)

elena86 wrote:
Count me in Sal.So we are 4 and counting :)

Make that 5 :D

I really hope to get one, love the Millie :D

What was the mule run at? I have the 52100 mule and am happy with it's performance. I have used it mostly in the kitchen though. I always grab the s110v or m4 mule for hunting and fishing.

You can count me in on a 52100 Military. Sounds great. There was talk of making a 52100 UKPK, I wonder if that is still in the works?

I wonder what color G10 they are going to be?

A multicolor would be nice I think, maybe black and red. :D :cool:

Would look nice with the patina that 52100 will have in time.