Sandvik Hardening Guide

Vivi said:
I haven't come across a knife steel that refused to take a good edge. Yet. I have noticed certain steels taking an edge much quicker than others though. VG10, 13C26, 12C27 and the steel Victorinox uses all sharpen very quickly for me. S30V, D2, ZDP-189 and S60V take more time to get a good edge. While I can get my S30V knives sharp enough to whittle hair, they seem to lose their ultra sharp edge quickly, then hold on to a decent level of sharpness for a very long time.
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I'm no steel expert but could it be that the weaker carbides in the larger
carbide steels are falling out(micro chipping?) leaving the stronger ones in place
that makes the steels stay decently sharp longer while the 13C26 with
smaller carbides still maintain a razor edge since you have smaller carbides
falling out?

Did that make any since to anyone?? :confused:
Because it kinda confused me while typing it out. :D
 
svrider3 said:
I'm no steel expert but could it be that the weaker carbides in the larger
carbide steels are falling out(micro chipping?) leaving the stronger ones in place
that makes the steels stay decently sharp longer while the 13C26 with
smaller carbides still maintain a razor edge since you have smaller carbides
falling out?

Did that make any since to anyone?? :confused:
Because it kinda confused me while typing it out. :D
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Yeah, pretty much. I think the carbides are equally strong although the large ones leave a bigger hole when falling out. The larger holes is the "dulling effect". A small hole will not have the same impact. That is the major difference.

Regards
//Jerker
 
thombrogan said:
A question for Jerker, Larrin, and our SA knifemakers:

How much of a beating can 12C27 or 12C27M take when chopping, digging, and prying as compared to such standby steels as 5160 and 1095 at hardnesses of HRC57-60? Would 7C27Mo2 be better if impact, prying, and twisting strength are valued over wear-resistance?

Many thanks!
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Hi Thombrogan,
At the same hardness the toughness (able to handle beating, prying etc) will be quite similar for all our fine grain steels (13C26, 12C27, 12C27M and 7C27Mo2). The problem would be to hit 57-60 with 7C27Mo2. There should be only a small theoretical difference and that is the carbide density. Higher density will decrease toughness so our grades should rate like this, starting with the best one: 7C27Mo2, 12C27M, 12C27 and 13C26 (19C27 will be the last one one since it's a coarse grade). My personal favorite for a "beater" would be 12C27, the slightly lower toughness will hardly be noticed but the extra wear resistance and edge stability would really benefit the knife.

A crack will always start in the weakest part of the steel. That is usually the largest carbide or the largest impurity. So comparing 12C27 with 1095 then 1095 should win if only carbides are regarded. If we also count purity (which Sandvik does quite well) then it's a matter of what steel supplier who has made the 1095. The purity level of their mill.

My personal opinion is that the toughness of 12C27 will be very close to that of 1095, but slightly lower. But better than any other steinless steel out there. Also better than any tool steel out there like D2.

Also hardness has of course a negative influence on toughness. Hard=more brittle. We recently did a toughness test (impact toughness) of D2 of 55 HRC vs 12C27 at 58 HRC. And 12C27 absorbed 3 times more energy before cracking. Which means significantly higher toughness for 12C27. Since the hardness difference benefited D2 the difference is big. We tried this since a lot of people consider D2 to be really tough. I consider it one of the most brittle steel grades in knives today. Only surpassed in brittleness by grades with massive carbide density such as ZDP. ZDP has tons of qualities, but touhness is not one of them.

Regards
//Jerker
 
Thanks very much, Jerker!

My knives and materials wishlist has again expanded (though if every "beater" were made from S7 and every "slicer" were made from M2, I still wouldn't mind).
 
Larger carbide grades lose initial sharpness quickly because the finely sharpened edge is smaller than the carbides, there is carbide pullout during sharpening, it is possible to get a very fine edge, but you have to get rid of the carbides first. The edge is unsupported by carbides so it wears quickly down to where the edge is properly supported by carbides. Fine carbide grades hold their initial edges better than coarser grades and coarser grades have the advantage in the long run. But who wants a knife that is semi-sharp for a long time?
 
Larrin said:
But who wants a knife that is semi-sharp for a long time?
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Most of us, here. :o Benchmade uses mostly S30V and 154CM in their black and blue class lines; KAI does use 13C26 for their Kershaw knives, but most of their Shun knives use VG-10 and SG-2 and most of their ZT knives use S30V, 154CM, and 3V; and Spyderco has more VG-10 and S30V knives than they have H1.

I think the problem is that it's easier to get the carbidey steels up to HRC59-61 than steels such as 13C26, 12C27M, AUS-6, and AUS-8 and easier for the end-user to grind the low-carbide steels into edges too thin for their hardness level so even low carbide steels of an identical hardness to the high carbide steels could better be set up for edge-rolling well before the wear-resistance of the high carbide steels comes into play.
 
thombrogan said:
Most of us, here. :o Benchmade uses mostly S30V and 154CM in their black and blue class lines; KAI does use 13C26 for their Kershaw knives, but most of their Shun knives use VG-10 and SG-2 and most of their ZT knives use S30V, 154CM, and 3V; and Spyderco has more VG-10 and S30V knives than they have H1.

I think the problem is that it's easier to get the carbidey steels up to HRC59-61 than steels such as 13C26, 12C27M, AUS-6, and AUS-8 and easier for the end-user to grind the low-carbide steels into edges too thin for their hardness level so even low carbide steels of an identical hardness to the high carbide steels could better be set up for edge-rolling well before the wear-resistance of the high carbide steels comes into play.
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Up until recently the fine carbide steels were not readily available to custom makers. The factories only went with the cheapest steels available and for higher end productions and customs they went with the perceived high performance steels. The answers to the questions are easy, we don't have to debate why people don't use them, only the actual performance qualities of these grades. The forgers all tout the abilities of their fine carbide, high toughness steels. It is very easy to heat treat 13C26 to 60 Rc. H1 is much more difficult to work with so it's not hard to imagine why they have fewer knives in it, and H1 doesn't exactly have much as far as carbide volume, it's not the same as 13C26 or 12C27.
 
Thanks, Larrin. I thinking more along the lines of AUS-6 and AUS-8 versus 13C26. Speaking of which, I really wish the Aokis chose 13C26 over 19C27 for their INOX line. Considering what they do with shiroichiko and shironiko, 13C26 would've been distinguishable only by the lack of patina.

Are you going to make any wa-gyutos soon? :)
 
thombrogan said:
Thanks, Larrin. I thinking more along the lines of AUS-6 and AUS-8 versus 13C26. Speaking of which, I really wish the Aokis chose 13C26 over 19C27 for their INOX line. Considering what they do with shiroichiko and shironiko, 13C26 would've been distinguishable only by the lack of patina.

Are you going to make any wa-gyutos soon? :)
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I hope so, we'll see. It's difficult to acquire/fix equipment while just trying to make it going to school. 13C26 would definitely be a step up. I don't know much about AUS-8, it could probably be taken harder than they do, but we can't do much about that.
 
It's probably just as well regarding the Aokis and folks that run AUS-8 and AUS-6 on the soft side. Those production knife company mindcontrol rays don't keep steady checks and benefits in the hands of their employees.

Forgive my selfishness, but are you going for an 8 or 12 year degree?
 
So, 13C26 wa-gyutos in three and one half years? :D

I prefer a 9.5"-10.5" blade ground as thin as my L. Thomas Santoku; but with very little belly; and would really dig an octagonal handle made from green linen micarta (no need for a ferrule) if you have a waiting list.
 
Larrin said:
Larger carbide grades lose initial sharpness quickly because the finely sharpened edge is smaller than the carbides, there is carbide pullout during sharpening, it is possible to get a very fine edge, but you have to get rid of the carbides first. The edge is unsupported by carbides so it wears quickly down to where the edge is properly supported by carbides. Fine carbide grades hold their initial edges better than coarser grades and coarser grades have the advantage in the long run. But who wants a knife that is semi-sharp for a long time?
Click to expand...

thombrogan said:
Most of us, here. :o Benchmade uses mostly S30V and 154CM in their black and blue class lines; KAI does use 13C26 for their Kershaw knives, but most of their Shun knives use VG-10 and SG-2 and most of their ZT knives use S30V, 154CM, and 3V; and Spyderco has more VG-10 and S30V knives than they have H1.

I think the problem is that it's easier to get the carbidey steels up to HRC59-61 than steels such as 13C26, 12C27M, AUS-6, and AUS-8 and easier for the end-user to grind the low-carbide steels into edges too thin for their hardness level so even low carbide steels of an identical hardness to the high carbide steels could better be set up for edge-rolling well before the wear-resistance of the high carbide steels comes into play.
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That depends on what you are cutting and how you define "semi-sharp". My experience with lower carbon steels is that blades made from them soon become too dull to cut the things I wish to cut. My experience with 440C, 154CM, N690, and VG10 is that blades made from them stay sharp enough to be functional longer. So they work for my cutting needs longer than lower carbon steels, even if they do not maintain an absolute razor edge as long.
 
knarfeng said:
That depends on what you are cutting and how you define "semi-sharp". My experience with lower carbon steels is that blades made from them soon become too dull to cut the things I wish to cut. My experience with 440C, 154CM, N690, and VG10 is that blades made from them stay sharp enough to be functional longer. So they work for my cutting needs longer than lower carbon steels, even if they do not maintain an absolute razor edge as long.
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But you haven't tried 13C26? Do you feel the same way about carbon steels?
 
Larrin, I have admit that I have not yet tried it, but it is on my list of alloys I want to try.
I have not had the same problems with 1095 that I have had with low carbon stainless.

I understand that some folks need or prefer a razor edge for the cutting jobs they do and I realize that it is possible that a 1%C may not be the best for them. I understand the concept of carbides tearing out. I just find that, if it is happening, it does not interfere with the cutting I do. Perhaps I personally do not need a razor for the cutting chores that I perform. I do need, or at least prefer, something that stays pretty darn sharp for a spell. Stainless steels with ~1%C have done that for me. Stainless alloys with 0.8% or less have not performed as well at edge retention when performing my cutting tasks.

I know it's a matter of semantics, and I know that it is hard to find a terminology upon which all can agree. I would submit to you that perhaps the term "semi-sharp" is not quite the term that should be to describe the perfomance of 1%C stainless steels. (how about "less than razor"?)

regards,
Frank R
 
knarfeng said:
Larrin, I have admit that I have not yet tried it, but it is on my list of alloys I want to try.
I have not had the same problems with 1095 that I have had with low carbon stainless.

I understand that some folks need or prefer a razor edge for the cutting jobs they do and I realize that it is possible that a 1%C may not be the best for them. I understand the concept of carbides tearing out. I just find that, if it is happening, it does not interfere with the cutting I do. Perhaps I personally do not need a razor for the cutting chores that I perform. I do need, or at least prefer, something that stays pretty darn sharp for a spell. Stainless steels with ~1%C have done that for me. Stainless alloys with 0.8% or less have not performed as well at edge retention when performing my cutting tasks.

I know it's a matter of semantics, and I know that it is hard to find a terminology upon which all can agree. I would submit to you that perhaps the term "semi-sharp" is not quite the term that should be to describe the perfomance of 1%C stainless steels. (how about "less than razor"?)

regards,
Frank R
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But you haven't tried 13C26 then. 13C26 has greater wear resistance than 1095. If you are seeing greater performance with 1095 than 13C26 you aren't heat treating the 13C26 correctly. But since you have generically referred to "low carbon stainless" thus far, I will assume you haven't tried 13C26 or 12C27. It's different. Try it, you'll like it. :)
 
Larrin said:
But you haven't tried 13C26 then. 13C26 has greater wear resistance than 1095. If you are seeing greater performance with 1095 than 13C26 you aren't heat treating the 13C26 correctly. But since you have generically referred to "low carbon stainless" thus far, I will assume you haven't tried 13C26 or 12C27. It's different. Try it, you'll like it. :)
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It's on my list to try.
I'll have to go with Kershaw's heat treat, which I believe is not bad.
 
By the way 13C26's rope cutting performance is quite good (surprised even me). Search for Phil Wilson's testing, it's almost on par with 154CM.
 
Jerker, could you please provide the composition of Sandvik 14C28N steel, and how it compares to 12C27 and 13C26? Thanks, John.
 
Razorsharp244 said:
My personal opinion is that the toughness of 12C27 will be very close to that of 1095, but slightly lower. But better than any other steinless steel out there. Also better than any tool steel out there like D2.
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This is why Next Generation KaBar USMC were originally made from 12C27 by design group. I very happy to have that one.

Thanks, Vassili.
 
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