blade thickness????

K

Ken H>

Joined
Dec 31, 2011
Messages
4,562
Hello all, Got a question here. Since thin AEB-L is no longer available, just how much difference will there be in slicing with a 2" wide chef type knife for a .098" vs a .070" thick blade using a full flat grind? 1.4º vs 1º bevel angle. That's not much at all.

How about for a 1/2" wide paring knife blade? That's a 5.5º vs 4º bevel with FFG.

For paring knife blades it won't be much to thin them down a good bit on the grinder, but takes a good bit of grinding to thin a 2" X 8" chef knife down.

Ken H>
 
I do most of my chef's knives in 3/32", and I think it's great. At that width, even 1/8" or more is fine. On paring knives, you get a lot of wedging when you go above 1/16"--3/32" is no good in my experience.

Chris
 
Say Heah Boys and Girls, For me a thickness on a blade and a sharp edge are two different things, I personally like a strong blade, I exclude this from kitchen knives, In the bush where I pay attention to my blade thickness is where I use my knives most. Even Mors Kochanski talks about it in his book. I like "strong" because I can get a edge sharp enough to cut anything I need to in the bush. I also carry a 2knife system. The controversy between "Bush Craft and Survival Knives" is simple, I carry both. For example, One of my Fav's is my A-1 and H-1, Even though some say the H-1 is a hunting knife, Its similar to one of my all time Fav's. Bush Craft knives, My 3V Skookum Bush Tool, Thank You Mr. Rod Garcia. with my A-1, I know I could survive with it, and its exceptionally strong, and very sharp. Same with my H-1, I could twist apart kindling all day long and its also very strong, and it can take it, but its also a good Carver. Oh, I like thinner blades, But most of the time I team it with a thicker blade, Infact I made a very lite Piggyback, I put a nylon belt loop with a handle strap on my Bokor Black Vox Rold, The strap ended up to be a little long, so I slid my Mora Classic #1 on it, I carry a Hatchet and Saw with this great wood working combo, I wood process with my Hatchet and Saw, But I can still twist my kindling with my Bokor Vox Rold, I piggybacked it with my Classic #1, Infact this weekend and we're already here, I brought my Fox Bushcraft Parang which I teamed with my Frost Mora Clipper MG, a near perfect color match, But I just know the two knives will compliment each other. But when I Solo Scout, I'm prepared for a overnighter so I again like "Strong" I had a Piggybavk made for my Rodent 7/Rodent 3 which I Baldric Carry. I also have Vertical and Horizontal Carry, like my Benchmade Arvensis/Bokor Coye Ridgeback, for a lite Horizontal carry and my Ratweiler/Rodent Solution for my Veritical carry. So yeah, I could still have a strong thick blade that's sharp enough to cut everything I need to cut in the bush and still have a strong knife. Yeah, especially important when your away from civilization alone in the bush. But if I'm going to carve spoons or a netting needle, sure I'm going to use a thinner blade. But I don't think I'd be making a Netting Needle in a Survival Situation, Thanx You People, That's my $00.02.,,.

Sent from my SM-J700T using Tapatalk
 
Hey Ken, I only make kitchen knives and I use 3/32 or thicker. That said I still grind my knives extremely thin, around. 002" behind the edge but I do not always measure anymore. I thin and cut carrots until it feels right. I always come off the grinder and finish by hand om diamond lapping plates/stones/sandpaper. In the kitchen a knives performance is a lot more about edge thickness than spine thickness. That said at 3/32 I recommend strong distal taper on the last 3rd of the blade, you will get a stiff knife with a thin tip.
-Trey
 
The thickness of a kitchen slicer blade mainly affects weight.
The difference in the main bevel angle is insignificant (for al practical purposes) in performance between a .06 and a .12" blade thickness.
The thickness at the edge before sharpening is VERY significant. (I go to a near zero FFG edge before sharpening).
The edge angle is also very significant.

Distal taper eliminates most of the weight issue, so flex becomes that major factor in blade thickness.
 
TLDR = Too Long, Didn't Read.... I had to look that one up.

Stacy, Trey - thanks for confirming what I was thinking. I'd been stressing (as much as I'm capable of stress) about not being able to find AEB-L in the thinner stock. Plenty of .098" available, and I've got a bit on hand of 14C28N which I like.

My wife really likes light blades - even to the point of using none stabilized wood for less weight. I made her a petty 5" chef with .070" S30V with non-stabilized Koa and it's turned out to be her favorite knife.

Ken H>
 
This one is 3.55mm over the heel, with full distal taper to near zero. :)
Thick isn't necessarily a bad thing, depends what you want to do with it.

52100Gyuto-210x54.jpg
 
I think that .098" vs .070" would yield a noticeable difference in cutting ease, so long as you're maintaining similar thinness behind the edge. I might be biased - I like stock to be as thin as it will come. But that difference in thickness would be easily visible if you held the stocks next to each other.

Having said that, when you get down to .098", that's pretty thin enough to be a good cutter, especially if thin behind the edge.

I know - you could do a pair of blades from each stock, grind them to the same edge, and then compare! I would like to see the results.
 
While the 30% difference between the thicknesses seems a lot when comparing .10 to .07", the actual angle formed by the bevels only increases 0.8° on a 2" kitchen blade (2.0° vs 2.8°).
A 1/2" paring knife would have a larger angle difference ( 8° vs 11°), but slicing ease isn't as significant to the function of a parer. Even then, the 3° increase will not greatly affect cutting.

When comparing .10 thickness to .07, you could do all sorts of calculations, but if the blades are identical in size/shape/grind, finished to the same degree and sharpened identically, the difference in force required to slice something for a 0.8° increase would be so minute you probably could not feel it.

Note to Ken:
Your math on the angles in your OP was incorrect. You did the common error of using "degrees per side". This angle is only true for the angle formed by the sharpening stone and the imaginary blade centerline. While this is also commonly referred to as the "bevel angle", that is wrong. The bevel is a flat plane, and has no angle. The proper term for this angle is sharpening angle.
The edge is not made up from two angles ... it is one angle.
The edge angle is the geometrical angle formed by the intersection of the planes of the two bevels. In your case, the angles would be 2.0° and 2.8°.
The way to remember this is - you sharpen at 10° to get a 20° edge angle.


More on edge angles:
Far more important than a minor difference in spine thickness is the edge angle.
The edge angle can greatly affect the cutting ability of a kitchen slicer. However, it is a tradeoff between the edge sharpness and the edge life. Sharpening at 7° per side ( 14° edge angle) on a fish cutter will slice smoothly and almost frictionlessly. Increase that to sharpen at 12° per side (24° edge angle), and it may cut a tad slower, but the edge will last much longer. When testing an edge, start with it being the most acute you think is practical. I start a kitchen knife at about 15° edge angle. I give it some test cuts through cardstock to remove any wire remnants, and then do an edge flex test. If it chips out, I resharpen at 20° edge angle. To increase the angle only takes a few strokes on a stone, as it removes very little steel from the existing edge bevel. Decreasing the angle requires removing all the steel on the secondary (edge) bevel.

My starting edge angles are :
15° for kitchen slicers
20° for kitchen utility and veggie choppers
30° for hunters and utility knives
40° for heavy chopping and rough use blades.

To decrease wedging on a higher angle edge, convexing the edge angle into the bevel will reduce friction. This is best done on a 400 grit slack belt at low speed. I first sharpen the edge at the desired angle on a stone or against the flat platen, then repeat at the same angle on the slack belt. This method is very useful on hunters/skinners, which need both edge strength as well as slicing/cutting easy. The legendary cutting ability of a Japanese blade is merely a factor of the convex egde being both very sharp and very tough. In Japanese the support behind the edge is called niku, which means "meat". If a blade is a FFG, it is said to be without niku. If the edge is convex, it is said to have niku. In western terminology, we say, "A convex edge puts some meat behind the edge."
 
They need thin edges and low to medium angles. Carvers are where a thin blade is a real plus. .06" is a very thick carver to me. I think some of mine are probably .03". I do most of my carving knives edge angle ( yes, I carve wood, too) at 20° to 30°. Chisels and gouges vary, but 20° to 25° is a good edge.

A trick to make a carving tool edge last longer is to put on a microbevel at about 5° higher than the edge angle. If the edge was sharpened at a sharpening angle of 12.5°, then put a micro-bevel at 15° (25° edge angle with 30° micro-bevel on the edge. The micro-bevel is made by a single stroke down the hone at a slightly increased angle. It is the same function as the heel micro-bevel done on a graver.
 
Stacy, I guess my terminology was wrong, but the math is correct. When sharpening a knife I refer to the total angle as you did, but when setting up the angle to grind the bevel, I tend to think of angle to ricasso/tang. i.e. when holding blade to flat platen, it is held at half the total sharpening angle, or 1º, not the 2º sharpened angle.

Your comment about not being able to tell the difference is what I was thinking - when all other aspects of the blade are the same, the cutting on a chef knife will be hard to tell difference. Even with the thicker .098" blade, with it having a full distal taper from ricasso to tip, the weight won't be a hold lot extra.... perhaps an 2 oz or so more.

Thanks again for all the comments confirming my thinking on blade thickness.

Ken H>
 
Yes, I figured you were referring to the angle the bevel forms to the mid-line. I was just taking advantage of your post to point out that the edge angle is twice the number you posted. This is often a big issue for new makers who don't know what angle to use in sharpening a blade.
 
Good info and thanks for the post and replies. This not being able to get 0.070 stock is really throwing I kink in my operation.

Sent from my SM-G920V using Tapatalk
 
You must log in or register to reply here.
Back
Top