what angle for the edge?

[KennyB]

10-20 degrees (inclusive): Razors, chef knives, fillet knives
20-30: Skinning/game processing, whittling/carving,artisan crafts (leather and wood working for example), "everyday" chores like opening packages, busting boxes, cutting twine
30-40ocket knives cutting sturdier or more abrasive materials. Hard woods, lamniates, vynyls, pipe and lots of thick plastics. Rope, carpet, insulation materials. Tough synthetic type stuff
40-60: Axes... Splitting and chopping trees

I've seen lots of such lists and have seen people suggest what angle they like best for what type of tasks. This is generally what seems to be suggested

 

[unit]

Tried cutting up 2 pizza boxes with Navy k631 and Resilience, one each.

Same blade thickness, 3mm but Navy being narrower and I only convexed it a bit (not really thinning down the edge much), it loses to the Resilience with factory bevel. Resilience cuts better because of wider blade resulting in thinner steel behind the edge, even at 35-40 bevel.

Thick media will tend to reflect back blade geometry more...but this is not necessarily reason to give anything up in the way of performance.

On thick media if you hold the blade at a non-right angle (i.e. make the plane created blade intersect the plane created by the cardboard an angle that deviates greatly from a right angle). This technique will greatly reduce the pressure needed to make a cut by reducing the binding of the back blade in the media, thereby allowing you to experience the enhanced performance of a more acute edge bevel.

This is an example of how the skill of the cutter can trump the qualities of the tool...but combine skill and optimized tools and things really get fun!

 

[MrPocketsOfSteel]

Copy that David, notes were made and added. Thanks.:thumbup:

A lot of manufacturers of sharpening systems & tools have their own 'recommendations' regarding edge angle vs. intended use. Most or all of the guided systems (Lansky, Gatco, Aligner, etc) usually put that information in the product instructions (and can usually be found on the mfr's web site). Problem is, it's all pretty subjective and variable from one manufacturer to another. Not to mention, steel type and quality of heat treat makes most of the difference anyway, in determining what angle is 'best' for a particular blade. And each individual user, after getting acquainted with their own blades & habits, will form their own views about what 'works best' for them.

In very general terms, it's widely assumed most blades used for relatively common cutting chores (paper, packaging, food prep, etc.) will do fairly well at ~ 30 degrees inclusive (15 per side), and blades used for very hard use, such as chopping and cutting in very tough material, would do better with something around ~ 40 inclusive (20 per side). This assumption is seen in many/most of the V-crock style sharpeners (like Sharpmaker), which are almost universally set to sharpen at either/both of 30 and 40 degrees, or somewhere in between. Specialized cutting tasks, like carving/whittling (chisel grinds are common) and bushcraft (scandi grinds), and Japanese-style kitchen use (sushi, etc.), sometimes lean towards very thin edge angles at < 30 inclusive (sometimes much narrower, using quality steel that can support very fine edges).

 

[A.Dragg]

Man, I must be committing some huge act of blasphemy and completely bastardizing my collection for having almost all of my knives above 35 degrees inclusive. I just got a Kershaw Turbulence (which is such an outstanding knife) that I put a 32 inclusive angle on with a mirror polish and I have to admit, it cuts insanely. I cuts S-shapes into phonebook paper all day. Definitely better than my Sebenza Insingo with nearly a 40 degree angle (and Insingo is supposed to mean "razor" in Zulu!).

 

[mtangent]

30 degrees inclusive on everything. If the edge chips, I then up it to 40. I only need to go to 40 if the blade gets used for wood work.

 

[Chris "Anagarika"]

Thick media will tend to reflect back blade geometry more...but this is not necessarily reason to give anything up in the way of performance.

On thick media if you hold the blade at a non-right angle (i.e. make the plane created blade intersect the plane created by the cardboard an angle that deviates greatly from a right angle). This technique will greatly reduce the pressure needed to make a cut by reducing the binding of the back blade in the media, thereby allowing you to experience the enhanced performance of a more acute edge bevel.

This is an example of how the skill of the cutter can trump the qualities of the tool...but combine skill and optimized tools and things really get fun!

I was cutting it at about 40 degree downward, not vertical 90 degree downward like wood splitting/batoning. And still the Resilience won the day.

At the point where Navy started tearing, Resilience still cutting.

And yes, it was fun

 

[seelow123]

I normally keep my folders at about 25 degrees inclusive or less if I have the patience to to thin the edge out. I just recently did a PPT at 36 inclusive but will take it down about 10 degrees next time the edge needs fixin'. I don't use my folders for super hard work (except a select few) so the thinner the better for me.

 

[pwet]

I was cutting it at about 40 degree downward, not vertical 90 degree downward like wood splitting/batoning. And still the Resilience won the day.

At the point where Navy started tearing, Resilience still cutting.

And yes, it was fun

He is not talking about the angle relative to the ground, he talks about the angle of the cut, cutting with the blade angled sideways, not to the horizontal, so that the edges of the newly cut piece are beveled .... This changes everything.

 

[unit]

He is not talking about the angle relative to the ground, he talks about the angle of the cut, cutting with the blade angled sideways, not to the horizontal, so that the edges of the newly cut piece are beveled .... This changes everything.

Yes. You should end up with two pieces of cardboard that have a sharp edge where you cut.

 

[rlucius]

This Database may be of help:

http://www.wickededgeusa.com/index.php?option=com_joodb&view=catalog&Itemid=94

 

[Jason B.]

10-20 degrees (inclusive): Razors, chef knives, fillet knives
20-30: Skinning/game processing, whittling/carving,artisan crafts (leather and wood working for example), "everyday" chores like opening packages, busting boxes, cutting twine
30-40ocket knives cutting sturdier or more abrasive materials. Hard woods, lamniates, vynyls, pipe and lots of thick plastics. Rope, carpet, insulation materials. Tough synthetic type stuff
40-60: Axes... Splitting and chopping trees

I've seen lots of such lists and have seen people suggest what angle they like best for what type of tasks. This is generally what seems to be suggested

If this is all inclusive angles listed then every edge would fail due to the practical limit of the steel being surpassed by leaps and bounds in the given task.

Such angles in some cases are not even possible.

 

[Chris "Anagarika"]

Yes. You should end up with two pieces of cardboard that have a sharp edge where you cut.

To understand correctly, instead of 90 degree against the cardboard thickness, cut in say 45 degrees, so the cardboard ended up with 'chisel edge ' on each piece?

 

[unit]

To understand correctly, instead of 90 degree against the cardboard thickness, cut in say 45 degrees, so the cardboard ended up with 'chisel edge ' on each piece?

Yes, that is it.

 

[KennyB]

If this is all inclusive angles listed then every edge would fail due to the practical limit of the steel being surpassed by leaps and bounds in the given task.

Such angles in some cases are not even possible.

Well, I have several knives at 20-25 degrees inclusive ( as best I can measure ), and they all perform the tasks I listed in the specified range. I'm not really sure if I really read you correctly...

In any case, I was mostly recalling from this...

http://www.bushcraftuk.com/downloads/pdf/knifeshexps.pdf

Page 4, Table 1

Table 1 presents some approximate angles
used on blades for various applications. There does
not seem to be any published hard and fast rules for
what angles should be used for various applications.
For example, Leonard [1] recommends that 2&#946; for
knives used for applications such as cutting rope,
whittling tent pegs, etc. be at least 25o and
preferably 30o. If used only for skinning and
filleting a 15o value would be ample. The author has
found that a 2&#946; edge angle of 10-12o leads to rapid
edge deterioration on Rc = 60 knives in normal
kitchen use. Values of 20 to 30o are more
acceptable.

 

[leomitch]

There is a knife database being compiled by the Wicked Edge people...it is a compilation of knives with the steels and edge angles recorded as used by different sharpener guys. It is interesting to see the different angles used on the various knives. Anyone, not just Wicked Edge Sharpener users, interested can access this database and add their own data. Eventually this Wiki will become a valuable resource for anyone who sharpens knives.
If you are interested go to:http://www.wickededgeusa.com/index.php?option=com_joodb&view=catalog&Itemid=94

Cheers
Leo

 

[REK Knives]

I generally never go under 40 inclusive. The reason for this is that I've found this angle to be the sweet spot for most tasks.... It still slices really well but holds up for a good while. There is a trade off for lowering the angle.... It will cut better but will also chip and roll easier as well. So on my para 2 w/ cts20cp steel (the equivalent to s90v in edge durability) I keep it at 21*/side. This is because I noticed that when I dropped it down to 17*/side it degraded much quicker.... And I don't want to have to sharpen it any more than I need have to. I have a hard enough time keeping it from bunting and rolling as it is without lowering the angle and making the edge weaker. I look at it like this : I can either have an insanely sharp edge that will degrade quickly or I can have a very sharp edge that will last for a while. Guess I'm just the odd ball here

 

[tomsch]

I typically do a 30-35 inclusive with my Edge Pro and then touch up on fine stones using my Sharpmaker at 40 degrees inclusive. Makes it easy to touch up since there is not much steel involved and also gives a good balance between slicing and toughness. I'm still playing around with the correct angle for my custom kitchen knives to optimize edge holding and slicing capablity.