bm's s30v

I could be wrong, but I don't think sapphire and ruby are "aluminum oxide." They are harder.
 
I had the same problem w/ my Rukus using a sharpmaker, I could get it sharp but not sharp enough. Now I use diamond hones for all my s30v blades and it's easy to get them hair popping sharp.
 
monk3yfist said:
I had the same problem w/ my Rukus using a sharpmaker, I could get it sharp but not sharp enough. Now I use diamond hones for all my s30v blades and it's easy to get them hair popping sharp.
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I just got a Rukus in a trade and easily got it to whittle hair on the Sharpmaker. I also got my Caly 3 CF and others whittling hair on the Sharpmaker. My S30V Manix gets extremely sharp on the Sharpmaker as well, and most other S30V knives that I have used that are capable of taking a fine edge (I've ran into a couple that just have a crumbly edge once it gets to a certain sharpness) can be made to whittle hair, especially if you have the UF stones. I mainly use Benchstones, including my Spyderco ceramics, to sharpen knives now but the Sharpmaker is a fine tool as long as your backbevel is thin enough and you are doing microbevel sharpening. For me I have found Spyderco ceramics fine for S30V, CPM D2, VG-10, and all other steels except for it having off and on problems with microburring on ZDP-189 and it making my Super Blue and all hard M2 sharpening sessions cause microchipping. For those steels I generally use my Shapton Glasstones, which cut all steels real fast and clean, leaving a very nice polish, though I have heard of others having good luck sharpening Super Blue and All hard M2 (as well as tons of people doing fine with ZDP-189) with Spyderco ceramics. YMMV. As a note on diamonds, I use diasharps in XX Coarse, Coarse, and fine grits to cut through any steel really fast. I wasn't much of a fan of my X fine DMT however, but it was a 6"x2" that I never really took the time to break in. At that grit level I am plenty happy with the finish I can get out of the Spyderco ceramics and my Shapton Glasstones to not feel the need to take the time required to break in the X fine or XX fine DMT's. Maybe S110V or some steel like that would change my mind, but as it stands I am more than happy with my my current stones.

Mike
 
That's nice, gunmike, but which ones of all those steels you mention have larger quantities of Vanadium carbide? Raw hardness of the blade isn't the issue, it is the constituent makeup that appears to be an issue.

Wondered what role heat treat may play in this. I've observed that for a given steel, some companies produce a better blade for a given steel.
 
orthogonal1 said:
That's nice, gunmike, but which ones of all those steels you mention have larger quantities of Vanadium carbide? Raw hardness of the blade isn't the issue, it is the constituent makeup that appears to be an issue.

Wondered what role heat treat may play in this. I've observed that for a given steel, some companies produce a better blade for a given steel.
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The heat treat is a huge factor. Both Rukus I sharpened to a fine edge easily, same for my Manix. My Native doesn't get quite as sharp as the Manix but isn't bad, and it was actually Sebenzas that didn't take a good edge in S30V knives I've used. The other steel I have with a similar vanadium content (and higher hardness) is CPM M4, which gets incredibly sharp. I've never used the super vanadium steels like S90V, S110V, or 10V so I can't comment on sharpening those on ceramics, but up to S30V and M4 levels of vanadium I've had no issues. M4 actually whittles hair nicely off of a Spyderco medium stone when you do your part, and by UF you are just showing off. I throw in 3M lapping films which are AO to finish and they just keep on adding sharpness in 1, .3, and .05 micron grits. So, in my experience diamonds are not required for a fine edge on M4 or S30V (assuming the heat treat is good).

Mike
 
I've got a Mini Rukus coming this week. I'm thinking of microbeveling it. I have a BM Activator in S30V that chipped a few times on me. I'd rather not have that happen with the Mini Rukus. Anyone microbeveling their BM S30V blades?
 
Splat said:
I've got a Mini Rukus coming this week. I'm thinking of microbeveling it. I have a BM Activator in S30V that chipped a few times on me. I'd rather not have that happen with the Mini Rukus. Anyone microbeveling their BM S30V blades?
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What were you cutting to cause the chip and how bad was it?

A microbevel is just one of many ways to sharpen a knife, how were you sharpening the Activator?
 
Splat said:
I've got a Mini Rukus coming this week. I'm thinking of microbeveling it. I have a BM Activator in S30V that chipped a few times on me. I'd rather not have that happen with the Mini Rukus. Anyone microbeveling their BM S30V blades?
Click to expand...


I microbevel all of my blades. My Manix has excellent S30V and takes a 9 degree per side backbevel with a 15 per side microbevel and is pretty durable for EDC. For tougher cutting I fatten up the microbevel a few degrees, and in reality unless the microbevel is getting too big it doesn't make much of a difference in cutting ability if you use a 15 or 20 or even 25 degree microbevel, but I like to keep mine as acute as possible. My Rukus has about a 12 degree factory bevel, and it was microbeveled when I got it, so I went to the 20 degree slots on my Sharpmaker and had it whittling hair in a few minutes. I plan on rebevelling it to 9-10 per side for the backbevel and going with a 15-20 degree microbevel, depending on how it holds up. So far the Rukus is the only Benchmade I've come across that has impressed me with it's edge geometry, as a .017" thick 12 degree per side bevel is extremely impressive for a beast of a knife with a 4.25" blade.

As an aside, you can convex an edge to get similar results (many argue better results) to the microbevel concept, as you end up with a thinner back bevel and thicker angle at the very edge for better durability just like the microbevel. Since I am not using a jig and just freehanding (unless I'm using the Sharpmaker, which I only use when I'm in a hurry these days) I get a tiny bit of convexing in my edges anyway just from the biomechanics involved in sharpening. So both my backbevel and my microbevel each has some convexing in them anyway, but there is a definate shoulder at the microbevel, unlike the rounded edge of a convex bevel. I am so used to my microbeveling and am happy with the results to the point I haven't taken the time to try convexing. One of these days I will get some coarser grits of 3M lapping film and try it on a mousepad, and worst case is I don't like it and can try using lapping film instead of stones for my regular freehand sharpening. The sticky thread at the top of this sub forum on microbevels gives you some good info on microbeveling and I believe convexing as well.

Mike
 
Greetings: The observation that the S30v in a Sebenza did not take as fine an edge as some other S30v blades just jumped out at me. I currently have seven knives with an S30v blade. Two Benchmade 940's, one 930, one Leek, one UK Penknife and two small Sebenza 21's. I have reprofiled and sharpened or just resharpened each of them using Gatco diamond stones and a sharpmaker. I was pleased with the results regarding increased sharpness in all but two of them. The two Sebenzas.
Well over thirty hours went into these efforts using primarily the Sharpmaker rods. It took quite a while to remove that much S30v with consistent precession and care. I figured I'd develop my technique by sharpening the less expensive knives before tackling the Sebenzas. Cosmetically the Sebenzas look fine but their cutting edge appears and feels ragged when compared to the Kershaw, Spiderco and Benchmades. The Sebenzas also seem to loose their sharpness faster than the others. I was attributing this to my imagination since all blades now have the same 30 degree edge bevel with a 40 degree microbevel. I was contemplating getting an Edgepro hoping that it would help me get the edge I was looking for.
The fit, finish, shape and quality material of the Sebenzas are excellent but their edge taking and holding ability is frustrating me. Since I am inexperienced in sharpening am I just a dope or is there anything I should be doing that I am too stupid to be aware of. Is there any technique or method that will allow me to get the same edge on the Sebenzas that I have on the other S30v bladed knives. Thanks. OldDude1
 
knifenut1013 said:
What were you cutting to cause the chip and how bad was it? A microbevel is just one of many ways to sharpen a knife, how were you sharpening the Activator?
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IIRC it was within the first week of owning the knife and I was cutting plastic banding straps. This was my only knife damaged from cutting them. I was highly PO'ed and swore off S30V but I've come to learn a lot more about knives since then. I was thinking of microbeveling my Mini Rukus just as a precaution.
 
My experiences echo Gunmike's.As I can sharpen my S30V blades on a hard Arkansas.
Which must be close to ceramic in hardness.It takes the toothy edge of the diamond off and gives a smoother, finer cutting edge.Which I like better.This then allows me quicker
sharpening the next time.It does the same for me on my S60V blades.So, one does'nt
have to use diamond for these vandium steels.Other stone material can cut it.DM
 
Ortho,The author of your site said "relative hardness of Arkansas stones" is... then stated washita which is the lowest, softest grade. There are atleast 5 recognized grades of Arkansas stones.With each becoming denser and harder.I have observed while
smoothing/resurfacing black hard Arkansas stones w/ a coarse diamond stone severely,
eat away on the diamond stone.Based on personal experience I'd say they are harder than that.Plus the fact that it did sharpen S30V.Also, I notice your site puts SC near diamond whereas Narfang's chart puts it "well below" diamond.Just an obervation.DM
 
All I can find is grades of arkansas stones is based upon density, not differences in the hardness of the constituent materials, i.e. "novaculite" - novalculite is appearently mostly quartz or silicon dioxide. Higher density, the finer the grit, the less likely the stone crumbles.

MOH scalars are different than Knoop scalars.
 
Ortho,Thanks.Yes,I realize the two charts express different standards but they should be close to each other within themselves.Also, while smoothing the Arkansas stones w/ the diamond I noticed the diamond ate away much quicker at the Washita than on the denser grades.ie.the Black Hard.Which would express a noticable increase in hardness.
Perhaps I need to do more research in this area.Thanks DM
 
65535 said:
Personally I found the 940 to be a bit of an odd ball. To get an angle I felt acceptable for the blade I had to remove the thumbstuds and sharpen it much steeper than possible with them attached. After that it was about the sharpest knife I ever owned or own.
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+10!

I did the very same thing, my 940 got face shaving sharp pretty easily, with an edge pro bevel, and again later when I convexed the edge, three possibilities here.
1. bad HT
2. bad job
3. both

guaranteed BM will replace your blade if it's a bad HT.
 
OldDude1 said:
Greetings: The observation that the S30v in a Sebenza did not take as fine an edge as some other S30v blades just jumped out at me. I currently have seven knives with an S30v blade. Two Benchmade 940's, one 930, one Leek, one UK Penknife and two small Sebenza 21's. I have reprofiled and sharpened or just resharpened each of them using Gatco diamond stones and a sharpmaker. I was pleased with the results regarding increased sharpness in all but two of them. The two Sebenzas.
Well over thirty hours went into these efforts using primarily the Sharpmaker rods. It took quite a while to remove that much S30v with consistent precession and care. I figured I'd develop my technique by sharpening the less expensive knives before tackling the Sebenzas. Cosmetically the Sebenzas look fine but their cutting edge appears and feels ragged when compared to the Kershaw, Spiderco and Benchmades. The Sebenzas also seem to loose their sharpness faster than the others. I was attributing this to my imagination since all blades now have the same 30 degree edge bevel with a 40 degree microbevel. I was contemplating getting an Edgepro hoping that it would help me get the edge I was looking for.
The fit, finish, shape and quality material of the Sebenzas are excellent but their edge taking and holding ability is frustrating me. Since I am inexperienced in sharpening am I just a dope or is there anything I should be doing that I am too stupid to be aware of. Is there any technique or method that will allow me to get the same edge on the Sebenzas that I have on the other S30v bladed knives. Thanks. OldDude1
Click to expand...

I'm pretty sure your sebenza issues are a result of the CRK heat treat, as I recall he leaves his s30v a bit soft, and since you have sebenzas... buying an edge pro shouldn't hit your pocket book too hard.
 
Skimo said:
I'm pretty sure your sebenza issues are a result of the CRK heat treat, as I recall he leaves his s30v a bit soft, and since you have sebenzas... buying an edge pro shouldn't hit your pocket book too hard.
Click to expand...
If it is soft then it should be easier to sharpen.
 
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