who's sharpening their knives w/ a 30 degree, single bevel?

[allyourblood]

i've been making an effort to profile my knives to a 40° edge, with a 30° back-bevel. i've noticed some of my knives seem like they could handle just a straight 30°. i'm speaking of the inclusive angle, of course, so we're talking 15° per side.

what's the verdict? if some of you are using a 30° bevel and that's all, i'd like to know what knife it is, and what your personal results have been. does it last? how often do you sharpen?

i'm not too interested in any other angles, unless perhaps they result in a thinner edge, since i'm using my Sharpmaker to maintain my edges.

abe

 

[Nosmo]

I have two blades sharpened to 15°. One is a German Tina and is used to bud roses. It cuts soft bark. The other is a thin carbon steel kitchen knife. This knife cuts against a soft cutting board.

Both knives stay sharp and I have not experienced chipping or deformation of the edge. Both are very thin behind the edge.

I think the trick is to select a blade and angle for a specific purpose and use the blade exclusively for that task.

 

[Stockman]

30 only on my Calypso Jr and 710HS, all others I use the 40 for the final bevel.
The Cal Jr gets used daily, the tasks are light duty( opening large parcels of paper, slicing plastic wrap and strapping, opening cartons ) which is better suited to a razor type edge and the 30 makes a difference. I give it a touch up on the white flats every couple of days and a light strop on a leather belt. The 710HS lasts and lasts even with the thinner 30 edge and it is my showcase sharp knife - M2 produces an incredible polished edge that takes some time to get there, but well worth the effort.

 

[allyourblood]

The 710HS lasts and lasts even with the thinner 30 edge and it is my showcase sharp knife - M2 produces an incredible polished edge that takes some time to get there, but well worth the effort.

interesting. thanks to both of you for the replies so far. i notice the extreme edge retention of my 806d2 and it's resistance to rolling, and was considering just taking 'er in to a 30° edge, and see how it lasts....

abe

 

[cmd]

I have 4 blades that are doing very well with a pure 30 from the sharpmaker. Interestingly they are all D2. One is on my Benchmade 705BW, the other 3 are on my Queen small abalone stockman. I had an 806SD2 and kept its PE section set at 30 and really liked it that way.

My 440V Native was great at 30 but not for long, it worked much better with a 40/30 combination bevel.

So far my S30V Military has only need an occasional strop (from a strip of carboard) to keep it wicked sharp, so it has not even touched the sharpmaker yet.

My S30V Sebenza is now the same way, but I did thin out the bevel towards the tip to make it 30 for the entire cutting edge. That was done free hand with bench stones then followed with a few swipes of the fine stones on the sharpmaker at 30 then stropped with cardboard.

For VG10, I only have a Cricket and it has a 40/30 bevel that is nice, but I have a VG10 Calypso Jr on the way direct from Spyderco (just under $35, shipped ) and that will be a lot of fun to play with. I'm thinking about starting with something a little under 30 and then getting it very polished...

Definitely go for straight 30 on the sharpmaker with premium steels, the worst that can happen is that it performs really well but does not hold the edge for very long. If that happens, then just put a secondary bevel on with the 40 angles and all is great again.

Chris

 

[allyourblood]

that was a very exhaustive list there, Chris. much appreciated! i think i'll try it with some of my higher-end knives, like you suggested. my Leek is already at a pure 30°, and it hangs in there pretty well for 440a (or whatever the heck). i also keep my Schrade stockman at a 30, but that's due to the thinness of the edge to begin with.

abe

 

[HoB]

I am pretty sure that modern well treated blade steels should be able to handle substantially smaller angles than 30 deg. inclusive, but once you get below 15 deg, the reprofileing work increases substantially and strops being it worth for me, so I usually stop at 30 deg inclusive. Spyderco aims for a 30 deg. angle for their factory edge on ALL of their knives (independent on the steel).

I think the reason why the 20 deg "microbevel" works so well is just a matter of sharpening technique (you are working essentially purely on the very edge), and not so much a matter what the steel can support.

Just for the record, traditional japanese vegetable knives are made commonly from Shirogami or Aogami (high carbon steel) hardened to 62-64 Rc will support about 12 deg. single bevel chisel grind. That means 12 deg. inclusive! The edge gets quite fragile though (chipping).

 

[klattman]

interesting. thanks to both of you for the replies so far. i notice the extreme edge retention of my 806d2 and it's resistance to rolling, and was considering just taking 'er in to a 30° edge, and see how it lasts....

abe

(Note angles below are inclusive, like the sharpmaker)

For D2, I would say go for it (30 degrees). As mentioned, if the edge does degrade, a few shots on the sharpmaker at 40 will have it back in no time.

For me, I use a 30 degree bevel on everything, THEN I use sandpaper to convex/round off the shoulders and polish the edge. FINALLY, I use the 40 degree sharpmaker _whites_only_ to get a very small 40 degree edge bevel. This is very easy to maintain with the sharpmaker, and you can go seemingly forever until you need to reprofile the 30 degrees. I even do my SAK blades this way and it works very well.

It comes down to technique for me: I can get a knife very sharp at 30 and by sandpaper, but that final 40 bevel right on the edge removes any technique flaws or uneven spots and gives a perfect edge. It ensures that the final strokes are right at the edge, and gets rid of any burr trouble. It's also much easier to touch up at 40 when you have a 30 degree back bevel, a few swipes does it. If you only use one bevel (30 degrees), each time you touch it up, you have to remove metal from the entire bevel.

So you have three options:
1. Single 30 degree bevel. (Takes more work to touch up/create).

2. Bevel 30/40 (Easy to touch up, strong edge, lower performance).

3. Bevel 25/30 (Easy to touch up at 30 sharpmaker, great performance, weaker edge(?), but you have to do the 25 (12.5 per side) freehand.)

Ideally, you probably want #1, but it's harder to maintain, so I would do 2 or 3. I think D2 should have no problem with 3.

 

[dialex]

Most of my knives are sharpened at 30°. However, at 40°, the edge seems to last longer.