Step up from 1084, is it even needed?

U

Utican

Joined
Sep 18, 2010
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Hi guy. I want to start off by thanking everyone on this forum for sharing the wealth of information. I made a decision to upgrade to paid subscription today. Thank you.

I have made a few knifes for friends and family and sold 4-5 so far. Nothing to brag about. Mostly scandi ground Puukos and Leukus. Made a couple of nessmuks as well. Lastly I made a Kiridashi for a myself and a couple of coworkers ( guys at work love those things) I use a steeper scandi grind simillar to what is seen on Finish Puukkos. My grind is 18 degree inclusive. I always micro bevel for durability. I like my knives to slice better and on Leukus I make that angle somewhat more obtuse. So far feedback has been great with slight complaint in edge holding compartment. All blades are made with 1084 from Aldo in 1/8 stock. I have a reliable electric kiln and have been quenching in olive oil heated to 120F. Blades are then tempered twice at 400F for an hour with a cold water cooling in between. Had blades tested for hardness and they reliably come back at 59-60 HCR. I then sharpen the blades using DMT aligner system in 300 - 600 - 1200 grit progression and strop to remove the burr on leather with chromium oxide in 0.30u (micron). I personally love 1084 and how easy it sharpenss and how sharp it gets.

So the question is should I look to start using different steel for better edge holding ability, and if so where to start.
 
Have you tried stopping at 300 or 600 for a toothy edge? Going up there are lots of choices.. stainless, tool, etc. Everything is a trade-off, just depends on what is most important for the task (price, toughness, edge holding, rust resistant). Some recommended to me were 3V, 154CM, D2, but there are many, many more options. I'm sure the other guys can ad some serious in-depth knowledge on ya if they have the specifics on your next projects (if they differ from what you've been doing).
 
Can you be more specific about what's happening with the edge? Rolling? Chipping? Actual wear?

I really doubt it's something a "better" steel will solve. It sounds more like the grind is not suited to what the knife is being used for. 18 degrees inclusive sounds awful low for a general utility knife, to me at least.
 
zhyla said:
Can you be more specific about what's happening with the edge? Rolling? Chipping? Actual wear?

I really doubt it's something a "better" steel will solve. It sounds more like the grind is not suited to what the knife is being used for. 18 degrees inclusive sounds awful low for a general utility knife, to me at least.
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I will have a look at 3 knives that have been in use for a few weeks days tonight and provide more detailed description. One is a puukko that that my bro skinned and sliced two whitetails with. Another two I am getting back from a test drive.
 
I should say that my brother uses steel to keep his edge up and he has no complaints. I do the same for leuku that I use daily in the kitchen and I hone it only once a year.

Meanwhile here is my prototype Leuku I have been using for three year now. Excuse the rough look, I made this one for myself and it has seen its share of tough love. Leuku is made with 1/8 1080 steel from admiral. Recently I intentionally chopped two whitetail shin bones with it to see what would happen. Here are photos. I just checked, after few strokes on my F. Dick Dickoron sharpening steel the blade is shaving sharp even in the area where you can clearly see the blade chipped.



kk

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Well I'll be. The damage shown in your picture looks pretty much identical to the row of ragged little nicks & chips my bowie got last time it was used on deer shin/leg bones.

damage1wq9.jpg

damage2sh5.jpg


This is 5160 Bainite at around 56-57 Rc. Deer leg bones are super hard and will damage pretty much any edge that's made thin enough for decent cutting. The only thing worse to hit is the teeth. The ribs and spinal column are quite noticeably easier to cut, and would not nick a decent edge- I've done it with an old butcher knife that was only 0.01" thick at the top of the edge bevel.

If this is the reason you got poor feedback on "edge holding", then easiest way to stop the damage is to make the edge twice as thick, at least twice as steep edge bevels/angles, and harder. And even then it would probably get nicked up unless you chopped carefully on a solid chopping block.
 
I would say, if your blades are chipping, you could maybe refine your tempering process to bring the hardness down a little bit. If they're chipping from someone skinning an animal then THEY should probably refine their skinning technique. The edge should never cut while facing bone. Bones should be cut with a hacksaw. Hell, I use a scalpel and very rarely use it. Once you make a lot of the main cuts you should be able to just pull the skin off.

Also, I'm a fan of polished/refined edges. I've never bought into the whole "toothy edge" thing.

I think 1084 is a very capable steel and the only reason to switch would be for marketing purposes. A lot of knife buyers don't know about 1084.
 
Ok I looked at the Puukko and it has no damage to it. The owner of that one has no complaints. He also keeps touching it up with the steel and did not need to re hone and he has been using it on daily basis. Im still waiting on the other two. I just might make my micro bevel a tad more obtuse and see if that fixes the issue for other users. Would it make sense to also try and bring my Leuku blades to 57-58 HCR. I have a feeling that the diamond hones give somewhat toothier edge, or less refined than water stones,if may say so. I am about to order some Naniwa water stones and see if gives smoother edge. I am still waiting for two kiridashis to come back for inspection. I personally thing 1084 is awsome and would hate to have to switch steels at this point.
 
the possum said:
. The only thing worse to hit is the teeth. The ribs and spinal column are quite noticeably easier to cut, and would not nick a decent edge- I've done it with an old butcher knife that was only 0.01" thick at the top of the edge bevel.

If this is the reason you got poor feedback on "edge holding", then easiest way to stop the damage is to make the edge twice as thick, at least twice as steep edge bevels/angles, and harder. And even then it would probably get nicked up unless you chopped carefully on a solid chopping block.
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That make sense, few days ago I used the same leuku to chop through neck bone on the deer with virtually no damage. Shin bone vs Leuku was a different story. I had no idea that shins are that much harder. :eek:
 
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Utican said:
after few strokes on my F. Dick Dickoron
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Careful now, I hear you can go blind doing that. ;D

Seriously though, get yourself a hacksaw. It'll zip through bone in a jiffy and your knife edges will thank you. I'd break the bone with two big rocks before I took my knife to it.
 
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Lesson learned, it was more of an experiment if anything. I also forgot to mention i did not observe any rolling of the edge. Anyone else use sharpening steel to keep their knives sharp?
 
JG Custom Metal Works said:
Careful now, I hear you can go blind doing that. ;D

Seriously though, get yourself a hacksaw. It'll zip through bone in a jiffy and your knife edges will thank you. I'd break the bone with two big rocks before I took my knife to it.
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I kind of should have known that was coming
 
Utican said:
Lesson learned, it was more of an experiment if anything. I also forgot to mention i did not observe any rolling of the edge. Anyone else use sharpening steel to keep their knives sharp?
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IMHO if the edge is chipping and not rolling then the steel too hard for what you're using it for. You could either refine your technique or soften up the steel a little via the tempering process. As far as sharpening is concerned, it's my understanding that using a steel just straightens out the "teeth" on the edge and doesn't refine it at all. It's just a temporary fix as they'll just mash back over after a little bit of use. I'd rather carry a small stone out with me into the field and then maybe a small fine ceramic hone to remove the burr.
 
Utican said:
Watch this, I have to try if this works. Murray Carter's take on simillar issue.


http://www.youtube.com/watch?v=dU3ALY8OmZk
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And he pretty much just expanded on what I said, aside from his comments on grain structure. His last two reasons for chipping were: improper forging/tempering leading to a brittle edge or all forging/tempering was done properly and the knife was just used beyond it's purpose or capacity. As I said before, if the purpose of a knife is going to be chopping bone then you're going to want an edge geared more towards toughness, i.e... 56-57 Rhc. If you want an edge that will be used skinning then you should be able to get away with higher hardness numbers but you'd want to try and not push it beyond it's limits by knocking it into bone.
 
Your inclusive edge angle is the first thing that jumps out to me. If the heat treat and temper are solid, I wouldn't think 59-60 Rc is too hard for 1084, although it may be right on the border. IMO, 18 degrees inclusive is too steep for your design. That's the edge angle I would put on a fillet knife. I like my edges really thin as well, but you have to keep in mind your design and it's intended use. I would suggest bumping your inclusive angle up to 25 degrees and retest. That's what I use on my hunting knives and it's still plenty thin to slice like a scalpel, but has enough "meat" to the edge for some durability. For my "utility" style knives, I use a 30 degree inclusive bevel. I use 52100 at Rc 60 (which is kinda on the border for hardness with this steel) with those 25-30 degree edge angles, and haven't had any issues with edge chipping in my own tests or any reports of edge chipping issues from my customers. Also, the DMT aligner is garbage IMO. I have one. Used it once and never touched it again. It's impossible using that plastic guide, plastic clamp, and the preset notches to give you accurate and repeatable edge angles. The guide will begin to deflect immediately when clamping the knife in place (or at least mine did), and renders it useless. I now use the KME diamond system. All steel guide and clamp with a ball pivot similar to a heim joint for the guide rod. It's very accurate, infinitely adjustable, and repeatable. Lastly, edge retention with 1084 should be pretty decent but not necessarily stellar. As you know, it's not a "super" steel. If the primary intended use of the knife is to cut more abrasive materials, then I would suggest looking into a steel with more wear resistance.

My 2 cents.
 
Dang, I missed the 18 degree inclusive bit. The thinnest I do for scandis is 20 degree inclusive and I think that is pushing it. I think traditional scandia, i.e... from Scandinavia are either 11 or 12 degree edge angles. Also, I'm not gonna be pushing an edge like that very hard either. I mainly just use them for carving or, wait for the buzzword... Bushcrafing. :D
 
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18 degree inclusive sound pretty low. You should really increase edge angle, and if you don't want to sacrifice much cutting capability you can also reduce be-hide edge thickness and convex the edge.
 
Ok I shall make a test blade in 20 degrees and 25 degrees and see how it stacks up.

Adam what other steels would you look in to for my application?
 
Utican, I have a supply of 1.2519 from Germany. It is like O7, 110WCrV5, and VERY similar in composition to Blue#2. I recently made a hunting knife from it, normalized, thermal cycled, austenitized at 1475F with the proper soak. Temper was walked up to 400F. I grind the edge VERY thin, then sharpen it at a low angle, then polish off the edge shoulder, then all that is left is about .005" or less for a micro bevel of 30 inclusive (15 per side). That steel is a definite step up from 1084.

I had the exact same thing happen. The edge was pushed a little too hard for the angle/grind I have on it, and had about 3 or 4 very very small chips that easily came out with touch up. Edge went thru pelvic bone, or it started to anyway before I decided to use the loppers. Not really what my design/geometry excels at...going thru bone!

The point being.....a better steel probably is not the right answer in your situation. 1084 is quite a good steel. All the advice has been given....just wanted to let you know. Adjust your edge angle a bit and go from there!
 
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