Sharpening difficulty for different steel.

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nozh2002

nozh2002

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I just recently did some sharpening tests for 4 Bucks 110 with steels 402HC, BG42, CPM154 and CPM S30V.

I see no difference at all!

There is no difference in sharpening medium carbon 420 vs high vanadium CPM S30V vs high carbon BG42 and CPM154. I also may say thet I found no difference in sharpening D2, M2, ZDP189, A2, 110x18MShd, 1095...

However I hear a lot of statements that this steel is good but too hard to sharpen for regular user or even impossible and only me and you can do this but not regular customer etc...

My questin is what is the basis for this statements? If any? I use Diamond Product benchstones 400 and 1200. both allow me to sharpen anything shaving sharp.

In theory abrasive always much harder then any steel and harder then many carbides in steel. So amount of steel taken out from the surfase depends on abrasive size not on steel. If it is 20 microns it takes 20 microns of steel is it 420 of ZDP189, does not matter, I think.

Only thing I can imagin is - soft steel is actually straighten out by benchstone flat and hard surfase, but not really weared out by abrasive. Or may be wetstone itself soft and wear out somehow, not sharpening blade.

But I suspect thet there is no really difference and this is widely used for marketing reasons - remember CPM 440V was "convicted" to be hard to sharpen. Any thoughts?

If somebody experience this sharpening difficulty - what was the sharpening device?

Thanks, Vassili
 
I've really only noticed a big difference when reprofiling. My S30V, D2, and BG-42 blades took a lot longer than 420HC and 1095 blades did. I do notice that it seems that I can get my SAKs shaving sharp in just a few swipes on a stone while the fancier steels take a bit more work, but that might be imagination.

Gordon
 
much, much easier to see a difference when working with arkansas stones. It's also apparent when you have to remove enough metal to eliminate the presence of chips in the edge. Even on ceramic and diamond, I can feel the lack of bite when making light passes with wear resistant steels. I was really surprised when I made my first few swipes on a stone with a D2 Queen, it really did feel different compared to the AUS8 I had most often used at the time.

But I will say that with a decent range of grits of hard materials (my 'softest' I believe is the chromium oxide, which is still ~3 points harder than Arkansas on the Mohs scale) I don't find much of any difference working M2, S30V, 154CM, etc. Thinning the edges from the outset is critical.
 
I think hardheart put his finger on it.
I think the fact that you were using diamond stones may have something to do with the lack of differentiation between steels. And diamond cuts faster than other media, so there may not be as much perceived difference. Lotta people don't use diamond.

It might be interesting to perform the same sharpening experiment with something like Sharpmaker ceramic sticks and see if you can see a difference then.
 
I would guess that these were all relatively recent 110's with the Edge-2000 hollow ground blades. The thin edge profile for the Edge-2000 blades is easy to sharpen. Using a diamond hone also reduces the effect of various alloys. Using a 1200 grit hone will not give you a fine enough edge to notice some of the differences between the alloys. If you used something like an ultra-fine ceramic rod as a final step you would probably notice a difference between the BG42 and HC420 verses the CPM steels. The CPM steels won't get as sharp.
 
I have seen some significant differences between steels on heavy profiling. Has nothing to do with sharpening. Once you want to remove significant material I find it becomes quite apparent. Well even while sharpening you see how quickly you can remove scratches from a prior grit, but again this is only tangentally related to sharpness. Personally, I found in particular 420HC difficult to SHARPEN (more difficult than others) because the two samples that I have (or had I have given up on them by now) form very floppy burrs which are a pain to remove. As Jeff already pointed out, this is already somewhat noticable but becomes much more pronounce on finer grits. On very fine grits you can notice that some steels polish better than others and their ultimate pushcutting abilitiy varies accordingly. For S30V it takes much longer for example to achieve a full polish for a given grit.

However, for the most part I would agree with you Nozh. If the blade is properly profiled and you are only sharpen on a microbevel, to a good shaving sharp, you won't see much of a difference, unless you have burr problems.
 
Jeff Clark said:
Using a 1200 grit hone will not give you a fine enough edge to notice some of the differences between the alloys.
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I can understand this, but many manufacturesrs reffer to "average Joes" and I guess this sharpness is beyond "average Joes" level of expectation.

knarfeng said:
It might be interesting to perform the same sharpening experiment with something like Sharpmaker ceramic sticks and see if you can see a difference then.
Click to expand...

I have Spiderco Sharpmaker and Spyderco ceramic stones. Again I did not see difference. Only once with CPM S90V fine rods not able to make blade sharper - vanadium carbides - 9% of CPM S90V steel harder then Aluminium Oxides and size of them is comparable to working grid of Spyderco Fine (6 microns), so in that case it was blade actually sharpen ceramic. However that was again on my opinion over "average Joes" expectation level.

I can see differennce between 400 grid and 1200 grid, but steel does not matter.

If this difference is seen only on arkanzas stones, may be this is not steel fault that certain things does not sharpen it, and it will be fair to say that premium steel require accordingly good sharpening tools?

Thanks, Vassili.
 
Some knives and steels are a pain to sharpen. Knives with coatings, for example, load up the Shapemaker rods in not time. Reprofile a knife like the RAT series is almost impossible. Even just sharpenig them is a hassle.

With knive like that, I start with reprofiling. I clip some wet/dry sandpaper to the Shapmaker rods. Turn the rod so the groove is on the side. That way, if there isn't enough paper to clip to, the clips can still grab the paper by being in the groove. The friction of the sandpaper will hold them in place. Make the paper as tight as possible. I usually make a 40 degree crease in the paper. That seems to help.

I've have also glued leather (same as on the stope pad stated below) to some rods and I've been experimenting with those. I don't use them on the RAT that I talk about next. As I said, I'm still experimenting but they seem to hold some promise when it comes to creating a convex edge. I clip the sandpaper around them just like the plain rods, usually 220 grit.

For my RAT-3 and RAT-7, for example, I find them hell to sharpen on the Sharpmaker. The rods load up with coating and the bevel is wide so sharping takes forever. My technique is to reprofile with the rods covered with 220 grit at 30 degrees. After a complete reprofile, I then go to 40 degrees, still using the 220 grit. May need to change to a new surface of the paper, of course. I then do about 20-30 strokes per side to get a 40 degree bevel.

I then move to the stroping block. It's a 2x4 with 1/8" split cowhide tacked to it (smooth side up). I strope at 20 degrees with 400 grit then 800 grit.

My personal experience with trying to sharpen my RAT's on just the Shapemaker rods has not be very successful. It akes orever and never do et a real good edge. With this technique, it only takes a few minutes. Only need to do the 30 degree reprofile one time. That gets rid of the coating that loads up the stones. The creation of a 40 degree bevel makes for a more narrow bevel and therefore faster sharpening.

Here are a few pictures if anyone is interested.
http://www.putfile.com/pic.php?img=4542795
http://www.putfile.com/pic.php?img=4542796
http://www.putfile.com/pic.php?img=4542797
http://www.putfile.com/pic.php?img=4542798
http://www.putfile.com/pic.php?img=4542799

Regards
 
VTguy said:
very helpful actually BP do you ever just strop on the leather?
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No, it's there to help the paper conform more easily to the edge. Makes sharping much easier. For some knives that cut better when highly polished, I use a 1500 grit. Usually 800 is as fine as I go and even 400 for some knives. Some knives I got to 800 grit then do 2-3 strops on the 400. It give is a "saw" type of cutting effect that is great for some materials. Some materials like a polished edge (like shaving), but others like a little "rough" edge like meat. Hunting knives, for example, perform better if a little rough. I don't mean dull, I mean just not polished. Wood seems to like a polished edge. Just experiment.

I also plan to make a couple more stroping blocks then get some very find grinding/polishing compound. That's applied directly to the shiney side of the leather. Many convex grinds, such as many Bark River knives, are finished in that fashion. Haven't had the time yet, however.

Regards
 
What would a good compound to use be... or more importantly, where can I find stropping compounds?
 
knarfeng said:
I think the fact that you were using diamond stones may have something to do with the lack of differentiation between steels.
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The amount of material which has to be removed would be most critical. A 50% difference on one minute is still nothing significant. 50% on ten minutes though would be fairly obvious. When most people talk about sharpening being difficult for a type of steel they generally mean reshaping is difficult.

-Cliff
 
Buck268 said:
What would a good compound to use be... or more importantly, where can I find stropping compounds?
Click to expand...

This place has all kinds of different sharpening items. I'll post the link for the liquid componds but check out the whole site. Green used first then black if you really want a mirror finish. This would usually only be for convex grind knives. Usually green is fine enough.
http://www.handamerican.com/paste.html

Joe's FAQ is really good also. Plus I'll toss in another favorite of mine.
http://www.knifeart.com/sharfaqbyjoe.html
http://www.pinewoodforge.com/sharpening.html


Regards
 
This might sound abit simplistic, but I generally notice a difference in various steels by noting the actual number of strokes it takes to acheive the edge I prefer.
I use a Spyderco Sharpmaker and I notice that my H-1 Pacific Salt takes about 1/2 the strokes as my VG-10 Endura 4 to achieve the same level of sharpness.
So, VG-10 might not be "harder" to sharpen, but it does take more time and more strokes on the stone (thus more effort) than H-1 blade-steel.
 
nozh2002 said:
I see no difference at all!

I use Diamond Product benchstones 400 and 1200. both allow me to sharpen anything shaving sharp.
Click to expand...

You really can't tell any difference? I can usually tell quite a difference between steels even on my diamond stones. I'm not sure there's really a difference in the amount of time required (since if I know I have to remove a lot of metal, I just start with extremely coarse stones) to remove the steel, but I can definitely tell a difference in the "feel" of how the steel is working on the stone. The stone feels like it just "bites" more on softer and less wear resistant steels.

In regards to time, generally the burr removal is the biggest thing that makes a noticeable time difference between steels to me.
 
the possum said:
You really can't tell any difference? I can usually tell quite a difference between steels even on my diamond stones. I'm not sure there's really a difference in the amount of time required (since if I know I have to remove a lot of metal, I just start with extremely coarse stones) to remove the steel, but I can definitely tell a difference in the "feel" of how the steel is working on the stone. The stone feels like it just "bites" more on softer and less wear resistant steels.

In regards to time, generally the burr removal is the biggest thing that makes a noticeable time difference between steels to me.
Click to expand...

Well, I am in talking about generic excuse used by manufacturers or sales persons for not providing premium steel, blaiming steel like ZDP189 etc being impossible to sharpen by average Joe.

My point is that to make knife shaving sharp which is probably on the level of average user expectation there is no difference.

Feel is more psycological description - very subjective, my feeling is that for 400 and 1200 diamond stones there is no noticable difference between different steel, in terms of "ZDP189 not being possible to sharpen or reprofile". Yes, reprofiling also takes almost same time.

I agree with HoB that only blurr on softer steels makes it bit trickier to sharpen - but it is opposite to statement I am questining now. But this is more related to benging edge, not wearing it out.

So far I think that explanation of this things - which never happen to me, may be:

1. It is mecanical impact from hard stone to soft steel may make it came sharper faster then hard steel. But it is steeling not sharpening as I understand.

2. I may suspect that hard steel blade may just destroy some soft stones and so little o no sharpening happen because of this - something you may experience if push to hard on japanese water stones, actually carving them out.

Thanks, Vassili.
 
nozh2002 said:
Well, I am in talking about generic excuse used by manufacturers or sales persons for not providing premium steel, blaiming steel like ZDP189 etc being impossible to sharpen by average Joe.
Click to expand...

The reason a manufacturer would choose to use a non "premium" steel is that production would faster and, therefore, production cost lower. Some steels take more time to machine that others.
 
When I sharpen 154CM versus AEB-L I usually notice the difference. 154CM just does not take an edge like AEB-L for me, I have to work at 154CM a lot more. I don't know if grindability even has anything to do with it in that case.
 
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