What you guy think of a maker who use forge heat treating CPM-S35VN?

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shqxk

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My friend send a photo of a maker who heat treating CPM-S35VN by forge with none thermocouple or any blade decarb protection at all.

There are some people who told him that he does it wrong but he didn't give a shit.

I pretty sure he also doesn't has any kind of oven/kiln to do the proper tempering.

What I concerned is this guy pair his name with one of the most famous martial art trainer here so his work sold like a hotcake, $200 for 3.5" fixed blade and hundreds of them have been sold. Not to mention that cost of living here is 4 time cheaper than in the US, so you would get the idea..
 
Two things come to my mind here; one is "Caveat Emptor". I want my customers to ask me questions about my processes. Several great makers have told me it is a knifemakers responsibility to educate the knife buying public. An educated buyer will make better decisions on who they buy from and bad makers will either get better or leave the scene.

The second thing I'm reminded of is Harvey Dean telling me at a hammer-in that he can tell the temperature of his steel in the forge to within 50 degrees just by color. A person with enough experience and testing could probably manage to do acceptable HT on most any steel using only a forge and S35VN in particular can be tempered in a wide range of temperatures from 400 to 800 degrees. He could throw it in a toaster oven or a home oven for tempering. Also, S35VN is an oil or air quenching steel. Cryo is also highly encouraged but not a requirement. I suspect he could produce a usable knife if he's got decent skills but, he is not taking advantage of the strengths of S35VN.

In the end, it all comes down to the performance of the knife. Have you used one? How do they look? I'm playing devils advocate here but, if they have halfway decent cutting characteristics and look fantastic, I would think they would sell.

Just to be clear, I use a lot of CPM-S35VN. My process is to single wrap it in high temp tool wrap and HT in a 2-stage process in an Evenheat oven w/ Rampmaster control then plate quench. When cool, they go into LN for 20 minutes then get two 2-hour tempering cycles in the Evenheat. I believe this is the best way to have good control over the HT and I try to do my best on everything I do.

Bob
 
Heat treating high alloy steels in a forge is not the best way to go, in my opinion, but it can be done. Karl Schroen wrote an entire book telling how to do it.

Speaking for myself, I made a chef's knife out of 440c before I had my Evenheat oven. I hardened it in my forge and tempered it in my kitchen oven, and ten years later, it's one of the most used knives I have...
 
I know one maker who does his CPM 154 in the forge and seems to get great results. consistent 58-59Rc and hasn't had a complaint yet. like RangerBob said... might not be using that steel to its max without the cryo however, but nobody's complained ever.
 
I won't mince words here:
I think anyone who HTs a high alloy stainless steel, and especially CPM-S35VN, in an open forge is a fool.
Call Crucible/Niagara and ask a metallurgist from the folks who make the steel what bad things would happen to that good steel if you have any doubts.

The list of what is wrong with any such statement is long, but the top items are:
1) Temperature control - There is no way to tell 1950F by eye. There could be as much as 500 degrees in range that people may think is 1950F. Tests done with master smiths have shown how bad the eye is for judging temps. A magnet may give you a reference for 1400F, but that is a long way from 1950F.
2) Temperature regulation - There is almost no way to hold a blade at 1950F for 20-30 minutes without
3) Oxygen exclusion - unless the blade is wrapped in a sealed stainless packet, the surface would be damaged. I don't know how well a packet would hold up under direct flames in a forge, but suspect it would not do well.
4) Quality - I regularly read, "With good results" and a Rockwell reading as a verification that a knife is good. There is a lot more involved than that.....especially in a steel like S35VN.
 
^ this

Stacy E. Apelt - Bladesmith said:
4) Quality - I regularly read, "With good results" and a Rockwell reading as a verification that a knife is good. There is a lot more involved than that.....especially in a steel like S35VN.
Click to expand...

^ and especially this.

If a maker is going to charge custom maker prices they need to provide quality commensurate with that price. Using a forge for this kind of material is disrespectful to the ultimate naive customer.

Does it work? Probably okay, most of the time, in most of the blade. But I think it's an act of hubris and an irresponsible practice. There's just no way they're getting consistent results.

If I had one of those knives, I'd feel like someone who bought a new car and discovered it had been in an accident and repaired, or bought meat from a butcher that doesn't clean his gear etc.
 
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Don't get me wrong... I'm not arguing the point. I just happen to know a guy who does it with his stainless. I'm no metallurgist by any means. I send mine to peters or Rob and let them deal with it till i have enough money to get the oven i want.
 
I totally agreed with you Stacy.

This kind of behavior is definitely disrespectful and irresponsible to the customer.

Sadly the maker has so much fan boys and I would high likely to get crushed if I criticizing him:barf:



PS. This is his pic showing his heat treating on S35VN it is an open forge...:confused:

 
He cra cra. My daughter would say.
 
Someone mentioned that Harvey Dean can tell temperature by color within 50 degrees. To put that in perspective, that small range could be the difference between fine grain, tiny carbides and little if any RA and the opposite with a steel like 52100. It could mean the difference between an incredible hamon and a crappy one with W2. My understanding is that a lot of those CPM steels can be very finicky about time and temp control. I have effectively heat treated a lot of different carbon steels both in a muffle pipe in the forge with a thermocouple and later in my Paragon oven. But when it came time to HT CPM3V, I sent it to Peters because for starters, I did not have the setup for the cold treatment and it would have cost me about as much as having up to 200-400 blades heat treated professionally. at one time. I have seen the late John White hold small Fogg type forge to within under 10 dregs for a long period of time, but that was at like 1450F. I would not want to try that at 2000F.
 
Stacy E. Apelt - Bladesmith said:
I won't mince words here:
I think anyone who HTs a high alloy stainless steel, and especially CPM-S35VN, in an open forge is a fool.
Call Crucible/Niagara and ask a metallurgist from the folks who make the steel what bad things would happen to that good steel if you have any doubts.

The list of what is wrong with any such statement is long, but the top items are:
1) Temperature control - There is no way to tell 1950F by eye. There could be as much as 500 degrees in range that people may think is 1950F. Tests done with master smiths have shown how bad the eye is for judging temps. A magnet may give you a reference for 1400F, but that is a long way from 1950F.
2) Temperature regulation - There is almost no way to hold a blade at 1950F for 20-30 minutes without
3) Oxygen exclusion - unless the blade is wrapped in a sealed stainless packet, the surface would be damaged. I don't know how well a packet would hold up under direct flames in a forge, but suspect it would not do well.
4) Quality - I regularly read, "With good results" and a Rockwell reading as a verification that a knife is good. There is a lot more involved than that.....especially in a steel like S35VN.
Click to expand...

Nathan the Machinist said:
^ this

^ and especially this.

If a maker is going to charge custom maker prices they need to provide quality commiserate with that price. Using a forge for this kind of material is disrespectful to the ultimate naive customer.

Does it work? Probably okay, most of the time, in most of the blade. But I think it's an act of hubris and an irresponsible practice. There's just no way they're getting consistent results.

If I had one of those knives, I'd feel like someone who bought a new car and discovered it had been in an accident and repaired, or bought meat from a butcher that doesn't clean his gear etc.
Click to expand...

"commensurate"

but otherwise absolutely


But why pay a premium for premium material, then deliberately process it in an incompetent manner
 
12345678910 said:
"commensurate"

Grammar-Nazi-1613.png


but otherwise absolutely
Click to expand...

derp


:D
 
I know a place that can do it correctly for him for about $12 :)
 
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