all about angles

T

Tar18

Joined
Oct 3, 2012
Messages
144
Hi folks.
I have only been sharpening now for a short while. I have a Sharpmaker which I have enjoyed learning. I have done quite a few knives now but I came across a video on YouTube which showed him using a 40 degree angle. Now with the instructions that came with the Sharpmaker he was using the 30 degree angle. Now all of a sudden I am confused. Easily done :) :) Which angle is the best for kitchen knives, hunters, skinners? I have done up a few skinners for the guys up here that hunt and no issues from them. Again now not sure which angle and how do I decided which one is best.
I would really appreciate some help here for one that is learning and enjoying it.
Regards
Tar
 
There is no number of an angle that one can recommend, since it all depends on material to cut, steel, heat treat etc. But as far as my experience goes, a relief angle of about 10 dps and an apex angle (or Microbevel) of 15 dps works for almost all applications.
 
Unless you're using your knives very, very hard (sharpened prybar, screwdriver, etc), you should be fine at 30° or a bit less for most everything. If you do find a circumstance where your edges are dulling too quickly (or rolling, chipping) at 30°, you can always add a 40° microbevel to the 30° back bevel. That's actually what the Sharpmaker was designed for in the first place, and why it has the two different settings.

Try it at 30° for a while, and then see if you need or want to do anything differently. I think you'll be very happy with your edges at 30°, in all likelihood, and you might even find enough reason to go lower than that. Cutting improves dramatically at 30° and lower.


David
 
Thanks for replying. Since I am new at this could you explain 10dps and 15 dps. What does the dps stand for.
Sorry but just learning all of this.
Regards
Tar
 
Thank you David for the help. I am doing a set of kitchen knives now and one is chipped in several places. Not sure how the owner uses them but this is chipped. If I change the angle to 40 degrees on the Sharpmaker would that help this situaltion?
Second part to the question. how do you get an angle less than 30 degree?
Thanks for all of the help
Regards
Tar
 
Tar18 said:
Thank you David for the help. I am doing a set of kitchen knives now and one is chipped in several places. Not sure how the owner uses them but this is chipped. If I change the angle to 40 degrees on the Sharpmaker would that help this situaltion?
Second part to the question. how do you get an angle less than 30 degree?
Thanks for all of the help
Regards
Tar
Click to expand...

If there is chipping, it may be best to stay at 40°. Or, you might ask the owner specifically how he/she's been using the knives, and if they know how the chipping happened in the first place (maybe a single incident or poor choice of uses; who knows...). If it was an isolated occurance they don't intend to repeat, they might still appreciate working with the thinner geometry.

As for going lower than 30°, that usually happens by some other 'freehand' means, if/when you decide you're ready to try it. Either that, or some other more sophisticated guided systems (Edge Pro, Wicked Edge, etc) are also capable of going lower in angle.


David
 
Tar18 said:
Thanks for replying. Since I am new at this could you explain 10dps and 15 dps. What does the dps stand for.
Sorry but just learning all of this.
Regards
Tar
Click to expand...

Yes, thanks DeadboxHero, dps stand for degrees per side, so 15dps is an edge angle of 30 degrees inclusive.
Tar18 said:
Thank you David for the help. I am doing a set of kitchen knives now and one is chipped in several places. Not sure how the owner uses them but this is chipped. If I change the angle to 40 degrees on the Sharpmaker would that help this situaltion?
Second part to the question. how do you get an angle less than 30 degree?
Thanks for all of the help
Regards
Tar
Click to expand...

Yes, as soon as you want to go lower than 15 dps you may have to consider freehand sharpening. I used to recommend the Spyderco Sharpmaker in addition to a coarse waterstone/diamondstone/oilstone for a complete setup. You use the coarse stone to reprofile the knife below 15 dps and use the Sharpmaker for the final touch (Microbevel). I still use the Sharpmaker from time to time when I don't feel like putting any effort in feedback/control and adjustment, it is just so easy!
 
First post from a long time lurker here, but hopefully I can add something from my experience. My first sharpening system "smith guide" from a big box hardware store has instructions that tell you to use the 20 setting for kitchen knives, 25 for hunting knives. While I understand the reasoning behind this, finer edge for finer tasks, more obtuse angle for harder use knives, it can lead to a lot of confusion. I pretty much held to this philosophy until I bought my first Spyderco and discovered the micro bevel for the first time. This lead me to buy a sharpmaker and I now sharpen all my knives edc, hunting, kitchen with a 30 back bevel and 40 micro bevel and have no complaints. A fully apexed, refined bevel is going to cut well at any angle. The beauty of the sharpmaker is the ability to put a very refined cutting edge on your blade very quickly and touch it up with minimal effort. Setting the back bevel with the sharpmaker diamond rods can be tedious, but the work up front is well worth it in the long run.
 
sc00ts said:
A fully apexed, refined bevel is going to cut well at any angle.
Click to expand...

That's not necessarily true, depending on the intended use. For everyday cutting tasks, you probably wouldn't notice a great deal of difference between 15 and 20 dps. There is a huge difference, however, between 15 and 25, especially for slicing. For push-cutting applications, such as wood carving, you could have a perfectly apexed, mirror finished, 15 dps blade, and it would still be pretty worthless. For that, you need something more like 15 inclusive. Maybe more like 12.

A lot of literature from knife and sharpener manufacturers will recommend angles like 20 or 25 dps, mainly because these angles are easier to put on mass-produced knives, and clamp-style sharpening systems have trouble getting out of their own way, so to speak, at angles below 20, especially with smaller blades. Truthfully though, sharpening at these angles will pretty quickly lead to edge thickening, and, therefore, the need for reprofiling. As stated above, 30 degrees inclusive works very well for everyday tasks. If you manage to do serious damage to the edge, you were probably using too much force, or the heat treat was bad to begin with.
 
a relief angle of about 10 dps and an apex angle (or Microbevel) of 15 dps works for almost all applications.
Click to expand...

Sweet :thumbup:

I think it boils down to WHO is using the knife not who is sharpening it.
Some people could dull an ax cutting grape fruit.

I like the old Japanese Shokunin saying that goes very roughly : "A master is he who's tools are the sharpest yet sharpens least".
 
It's important to realize how much metal has to be removed if you try to change a blade from say 25 dps to 15 dps. If you attempt this, you'll notice that all of your grinding starts high up on the edge bevel, away from the actual cutting edge. Why? Because that's the part of the blade that is touching the stone, when held at the new angle (15 dps).

The SharpMaker is an awesome maintenance tool. But it's not really designed to do major angle changes. With the included rods you'll have quite a hard time changing angles more than just a tiny bit on most blades. The medium rods just don't cut fast enough.

Should you want to change angles, you'll either need much coarser rods for the SharpMaker, or bench stones, or some other system.

Brian.
 
Some members recommended pinching the sharpmaker rods using rubber band to go lower than the 30° setting. However, this is only slightly lower.
To go to 10° per side, it will not be possible with the setting.

To reprofile, it is better to have diamond or CBN rods (either will do). Lastly, there's slot on the sharpmaker to use the rods as free hand stones.

These are what I gathered from various posts & videos.
 
For all my kitchen cutlery, I use 40° on the SM. My santuko and boning cut easily and maintain their edge quite well.

For my EDCs, I use the 30° with a 40° microbevel.

You will indeed need something more aggressive than the SM's standard rods.
 
A little off topic, but not too far...

The Sharpmaker is a great tool for maintaining edges at 15 dps or 20 dps. I love mine and use it weekly (at least) to maintain the edge on my EDC folders. The medium, fine and extra-fine rods work GREAT for edge maintenance. However, IMHO, the Sharpmaker is NOT a good tool for most other sharpening task.

Like many people, I purchased my Sharpmaker when I first started sharpening. It was my first sharpener. As I progressed, I tried to use it for re-profiling bevels or repairing seriously damaged / chipped blades. I purchased the diamond rods, tried sandpaper, altered the angle of the rods and tried a few other common tricks to expand the functionality of the Sharpmaker. However, although it is possible to do other things with the Sharpmaker, I came to realize that the only thing that it does REALLY well is maintain edges that are already set at 15 dps or 20 dps. If I need to reprofile an edge or sharpen at an angle other than 15dps or 20dps, I pull out my KME, bench stones, files or strops.

Lest anyone misunderstand my comments, I LOVE MY SHARPMAKER. When used as intended, it is a great tool... it is just not good at everything.
 
Thanks folks for all of the helpful info. I am beginning to understand a bit more.
One more thing though. would someone explain 30 degree with a 40 degree microbevel.
I would like to try to understand "bevels" and what it means. Just one more thing in the puzzle.
Thanks again for all of the help.
Regards
Tar :thumbup:
 
Tar18 said:
Thanks folks for all of the helpful info. I am beginning to understand a bit more.
One more thing though. would someone explain 30 degree with a 40 degree microbevel.
I would like to try to understand "bevels" and what it means. Just one more thing in the puzzle.
Thanks again for all of the help.
Regards
Tar :thumbup:
Click to expand...

Normally, when we refer to "bevels," we mean the actual sharpened edge, i.e. the v-grind at the edge of the blade. This is also known as the "secondary grind," as opposed to the primary grind of the blade, which can be flat, hollow, etc.

There is a very good sticky in this forum about micro bevels, but the basic idea is this: You sharpen the blade at a given angle, say 15 dps. You then raise the angle a few degrees, like to 20 dps, and create a very thin "micro bevel" along the very apex of the edge. This is usually done with just a few passes on a fine grit stone, or, in the case of the Sharpmaker, medium rods followed by fine and UF if desired. The advantages are that the cutting edge is a bit stronger, yet will still slice better than if you had sharpened the entire edge at the higher angle. It is also very quick to resharpen, since you only have to touch up the tiny microbevel. This is really how the Sharpmaker is set up to do things; a 15 dps bevel with a 20 dps microbevel.
 
A quick and dirty explanatory drawing
F85CBA26-C792-4CE2-8CFE-5A5C0EF8779C_zpsmalli2fj.jpg

Take into account that the microbevel is usually difficult to see with the naked eye on the drawing is greatly exaggerated in its dimensions
Mateo
 
Tar18 said:
Thanks folks for all of the helpful info. I am beginning to understand a bit more.
One more thing though. would someone explain 30 degree with a 40 degree microbevel.
I would like to try to understand "bevels" and what it means. Just one more thing in the puzzle.
Thanks again for all of the help.
Regards
Tar :thumbup:
Click to expand...

The bevels are the 'flats' directly behind and to either side of the cutting edge; the 'apex' is the intersection of where two bevels come together at the cutting edge itself. A 'secondary' bevel is usually what you see near to the very edge itself (they usually form the 'factory edge' on most knives), and is applied 'secondarily' after the 'primary' grind is formed. The primary grind is what defines the overall profile of the blade itself, from the 'shoulders' of the secondary bevels all the way up to the spine of the blade. A 'micro bevel' is a very, very narrow bevel often, but not always, applied to the intersection of the secondary bevels, at a slightly wider angle; it'll often be almost too thin to see by naked eye (may be literally hair-thin), although some may be a bit wider.


David
 
Edge angles are different depending on where you are in the world. In US edge angles are normally around 35-40 degrees. In Scandinavia they are normally aound 20 degrees. We use 35-40 degrees on our forest axes.

In Scandinavia we do not chop with knifes, we only slice and whittle. If we need to chop we use an axe. That is a very old traditional thing here, we was a wood working nation for many thousends of years.

Our wood are mostly soft wood. The hardest wood we have are oak. Inncountrys with very hard wood they use higher edge angles. The climate, type of wood, type of games and so on decide the dge angles. There is no right or wrong here, edge angles develops from practical use.

Here is some traditional Sandi angles we use on our tools:

Total edges:
Razors = 9-15°
Kitchennknifes dor vegetables and meat = 20°
Kitchennknifes allround, 25-35°
Whittling knife for soft wood 18-20°
Whittling knife for hard wood 23- 25°
Allround knife 23° - honing edge 25-27 grader
Folders 20-25°
Hunting knife 20° Main edge 25° honing edge
Fishing knife, 19-20°
Filé knife for fish, 18-19°
Scissors 50-60°
Chissels 20-25°
Axe for carpenters, 25-30°, straight edge
Axe Forest use 30-40°, convex edge
Axe for splitting wood 40-55°, convex edge

Thomas
 
You must log in or register to reply here.
Back
Top