Why is 12C27 Good?

Chronovore

Chronovore

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I've been carrying budget knives since back before we had things like Blade Forums. I've had a bunch of different "budget steels". One of my favorites has been 14C28N. Looking at the elemental composition, the carbon content seems to belie its edge retention relative to other steels. The answer I usually see for this is nitrogen.

So I finally went to visit some distant family for the first time since the pandemic started. I happened to grab one of my Bestechs in 12C27. I naturally got roped into helping with a few chores which included cutting cardboard and popping zip ties. This got me thinking. While it's not a top performer or anything, 12C27 also seems to punch above its grade.

Looking at the composition, it has 0.6% carbon. Yet it seems to hold a better edge for me than 8Cr13Mov or AUS-8. It also seems more resistant to corrosion and it's easy to sharpen. Now that we've got experts like Larrin Larrin and better knowledge in general, I have to ask to why. What makes 12C27 as good as it is?
 
Chronovore said:
I've been carrying budget knives since back before we had things like Blade Forums. I've had a bunch of different "budget steels". One of my favorites has been 14C28N. Looking at the elemental composition, the carbon content seems to belie its edge retention relative to other steels. The answer I usually see for this is nitrogen.

So I finally went to visit some distant family for the first time since the pandemic started. I happened to grab one of my Bestechs in 12C27. I naturally got roped into helping with a few chores which included cutting cardboard and popping zip ties. This got me thinking. While it's not a top performer or anything, 12C27 also seems to punch above its grade.

Looking at the composition, it has 0.6% carbon. Yet it seems to hold a better edge for me than 8Cr13Mov or AUS-8. It also seems more resistant to corrosion and it's easy to sharpen. Now that we've got experts like Larrin Larrin and better knowledge in general, I have to ask to why. What makes 12C27 as good as it is?
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Good heat treat and proper edge geometry play a huge role in a blades performance regardless of the steel.
 
What he said; Heat treat absolutely makes or breaks a steel...

Think about it like leaving a cake in the oven too long or taking it out too early, or using the wrong temperature setting... You won't have a good cake... Regardless of what ingredients you used, following the recipe to a T, you can absolutely ruin an otherwise great cake simply by just cooking it wrong. Heat Treating steel is ultimately "cooking" the steel for a finished product. Everything else is just mixing the batter and prepping the pan...

Furthermore, 12c27 has been around for quite a few decades and was specifically designed with blades in mind, (used widely in razor blades early on), and as such has a very good balance of toughness, stainlessness, and very fine grained structure for very keen edges. With industry enhancements, the processes to make it have been really refined over the past 20 years or so, resulting in a much more clean and pure version with better overall uniformity then the original some 50+ years ago...

Not the same dynamic, but for comparison sake, and similar in regards to "better quality", compare something like 154cm or D2, both pretty good steels in their own right when manufactured and HT'd well, to PM-154cm or PM-D2...
Better cleaner more enhanced process to make an old classic steel, results in a better finished product. 12c27 isn't PM steel, but still, even the basic steel processes used throughout the industry have improved quite a bit since the 60's, especially by the high end specialty steel makers, (like Sandvik), and as such, the finished products have gained better, more uniform results...
 
I don't know anything about the processing of the steel. I have 3 Bark Rivers from the mid 2000's and they work very well.
I don't have to put much thought into keeping them sharp.. strop, steel or sharpen as necessary .
 
Thanks for the responses so far. I'll be reading the article that Larrin so generously provided.

In the meantime, I'm curious about the effect of heat treatment near the bottom tier. Everybody seems familiar with what the Bos heat treatment has done for Buck's 420HC. After disappointing experiences with Schrade, CRKT, etc.; I've been very impressed with what Civivi and Real Steel have done with 9Cr18Mov. I remember when the budget arena started flooding with Chinese D2 and all the controversy in comparing it to D2 from Benchmade, etc. It also seems like some steels are harder to get right. Is it the case that 12C27 is easy to get right or that the process has just been perfected for low-cost knives?

I ask because I'd figure that steels like 8Cr13Mov or AUS-8 should be better. I've had some blades in AUS-8 that hold a better edge than others but the average isn't great. There seems to be less variation in 8Cr13Mov, which is consistently mediocre. I've come to universally prefer the Sandvik steels in a budget knife. BTW, has anyone ever seen 8Cr13Mov with a really good heat treatment? I'd love to see Larrin Larrin explore the Chinese series of budget steels.
 
12C27 is remarkable as it is in the lowly 440A class of steels, yet performs much better. I understand that is in purer than other maker's steels and more refined. I think that, edge angle, and heat treatment have a lot to do with performance. Look at what Mora does with this low end steel. Amazing stuff.
 
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DocT said:
12C27 is remarkable as it is in the lowly 440A class of steels, yet performs much better. I understand that is in purer than other maker's steels and more refined. I think that, edge angle, and heat treatment have a lot to do with performance. Look at what Mora does with this low end steel. Amazing stuff.
Click to expand...
440A is quite different. They’re not in the same class of steel.
 
Chronovore said:
BTW, has anyone ever seen 8Cr13Mov with a really good heat treatment? I'd love to see Larrin Larrin explore the Chinese series of budget steels.
Click to expand...

Spyderco treats 8cr well. Kershaw does a pretty good job of it as well. Just got a Cold Steel Sr1 lite and they generally always have good heat treats so it should hold up fine.
 
I recently got a Leatherman OHT Multi and was surprised at how well it's 420HC blade performed.
Proper HT and Geo. make such a big difference. My Busse Game Warden in INFI steel doesn't slice as well or as long
as my Leatherman's wharncliffe in 420HC even though INFI is considered a higher end steel. It is, but that's not the point.
Both knives are made by quality craftsmen and both have proper HT. The geometry/ specs are very different though.

To me, I think you can use cheaper steels like 12C27, 420HC, AUS8, AUS6, etc. if you put the right amount of thought and design into
the blade itself. Blades that are made from a nice, thin stock and either deeply hollow ground or full flat ground cut well for a while just from
being so thin. The proper HT makes sure that knife being so thin doesn't cause it to snap too easily on you.

Different steels and super steels are great. The different steels, different geometries, and different heat treats are some of the things
that I enjoy most about the knife hobby. Trying out these different aspects and design philosophies of knives is the main reason
I buy so many different knives and have no staunch loyalty to any particular brand, steel, shape, etc. when it comes to knives.

Just about any knife that is crafted well and made by good people interests me.
 
Larrin said:
440A is quite different. They’re not in the same class of steel.
Click to expand...
I thought that aside from a little Moly they are quite similar. Am I wrong in this? I know 12C27 is pretty simple. Maybe I am thinking of another steel?
 
If you don't think heat treating makes a huge difference, at your own risk, get an old file and grind an edge on it.
Get an oxy-acetylene torch and some used motor oil. Play with it's heat treat.
Steel can go from ice cube brittle to copper wire flimsy...so to speak...
Dramatic differences in resulting steel from a few slight changes.

I also learned, it is very difficult or impossible to obtain a proper HT with a brazing torch and used motor oil
with a kiridashi made from an unknown steel with unknown temp./ parameters/ fluctuations the whole process through.
It is very very fun to play knife maker with fire and steel and grease and power tools though :D:D:D

I almost feel dumb showing y'all this but.....:rolleyes:
Here's the experiment and fun afternoon from a little while back :cool::p
7a74baca6ab59fc33992bd2e316ac46d9bdde2e7.jpg

Kydex isn't all that easy either but it holds the knife and it doesn't fall out
7eefa11c3eba82a5596f75526d84dc07c616b1e3.jpg
 
DocT said:
I thought that aside from a little Moly they are quite similar. Am I wrong in this? I know 12C27 is pretty simple. Maybe I am thinking of another steel?
Click to expand...
440A has 3-4% more chromium.
 
I've been highly impressed with my Manly Wasp in 12C27, HRC 60. The late Butch Winter (RIP 2004), who penned “The Steel Bin” column in Tactical Knives (RIP 2014) thought highly of 12C27. I saved his column, "12C27: A Steel That Gets No Respect" from a couple of decades ago. It is a fine-grained steel that, "properly heat-treated, is a steel to be reckoned with", Winter concluded. Sandvik says on its website, “12C27 is Sandvik's most well-rounded knife steel with excellent edge performance allowing razor sharpness, high hardness, exceptional toughness and good corrosion resistance. Continuous improvement over a period of 45 years has evolved it into the high performing steel grade it is today. The composition is tighter, the purity level is much higher and the fine carbide microstructure of today is far from how Sandvik 12C27 knife steel of the sixties looked. With a hardness range of 54-61 HRC, high toughness, scary sharpness and good corrosion resistance, Sandvik 12C27 is the recommended grade for hunting knives, pocket knives, camping knives, high-end chef's knives and tactical knives.”
 
I remember hearing the grain structure of 12c27 was very fine and that contributed to it taking a good edge when sharpening.
Please correct me if I’m wrong.
 
Getting older said:
Proper heat treat comes to mind.Can make or break a steel
Click to expand...
What he said.

Getting the most out of an alloy requires an optimized heat treatment. At the budget end of the spectrum, most knife companies don't take the time to develop an optimized heat treat schedule, because it costs time and money to do that. I've seen 8CrMoV blades at everything from 55 through 60 HRC. And who knows what the microstructure actually looked like.

Most steel companies provide minimal heat treat data for their alloys, and most of the time, that data is not designed for cutlery. So even with the starting data, a knife company would still need to do a lot of work to develop an optimized heat treat schedule.

On the other hand, Sandvik provides a nice heat treat chart for heat treating and tempering 12C27. Moreover, they give instructions for which times and temperatures to use to obtain a microstructure which is optimal for cutlery. That makes it easy for pretty much any companies to produce knives with better properties.
https://www.materials.sandvik/en-us/materials-center/material-datasheets/strip-steel/sandvik-12c27/
 
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