# sharpening angles



## stevenn21 (Nov 6, 2013)

hi guys im not very good with angles so would like to know when sharpening a knife on a whetstone instead of telling me in degrees can you please tell me in centimetres how high should i lift the spine of the knife off the whetstone for a scary sharp edge?

here is a diagram of what im asking:


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## Von blewitt (Nov 6, 2013)

Forget about angles and the height of the spine as that will change depending on the height of the blade.
Instead you should concentrate on the primary bevel, if you use the magic marker trick, you will ensure you are hitting the edge, then you can progressively lower the angle until you are happy.

Here is a Link to Jon from Japanese Knife Imports video which explains the marker trick
http://m.youtube.com/watch?v=8kzGvtX-h8g


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## Hbeernink (Nov 6, 2013)

yup- sure can. if (t) is the angle where you want the blade to be sharpened, AB is the distance to raise the spine (from the surface of the stone), and BC is the height of the blade (heel to spine at each individual point along the blade - note that this will change as blades are not a constant height...), then:

AB = BC * sin(t)


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## alex9635 (Nov 6, 2013)

About 0,7-1.0 cm.


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## Chuckles (Nov 6, 2013)

I was told there would be no math. :sad0:


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## ohbewon (Nov 6, 2013)

+1 The sharpie trick.


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## hobbitling (Nov 6, 2013)

I also find a 10x or higher magnifier to be helpful. I use a jewelers loupe. you can get one for under $10. useful for seeing wire edges and works well with the marker trick.


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## TB_London (Nov 6, 2013)

Assuming you're sharpening your Carter i would match the microbevel it came with using a magic marker.

People dont tend to work in absolutes, but if it'd be useful i could take a picture of my carter against the stone so you can eyeball the angle i use.


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## Ruso (Nov 6, 2013)

You can download the angle meter app for the smartphone and use it. 10-12 degree per side on a double bevel knife should give you a keen edge.


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## split0101 (Nov 6, 2013)

This is something that I have been struggling with also but in a different context. I know with sharpening it can get crazy with bevels, micro bevels, symmetry (or lack of it) but at the end of the day I think something like suggested angle guide for different steels would come in handy. For example you probably should not sharpen VG10 at a steep angle due to it being chippy (?). Over time unless you're a pro you are going to change that factory bevel and if you bought a used knife then all bets are off. Having a steel reference would help.


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## hobbitling (Nov 6, 2013)

So is there a guide for which angles to use for different steels/hardness, and different types of knives?


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## split0101 (Nov 6, 2013)

hobbitling said:


> So is there a guide for which angles to use for different steels/hardness, and different types of knives?



I don't think so. I looked around but could not find a complete reference. When I wanted to sharpen my Carter for the first time I looked around the forum to see how guys sharpen white #1. 

I think having a "general" guide/table would be very useful, especially to the novice/intermediate sharpener.


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## hobbitling (Nov 6, 2013)

for the math-phobic, use this. http://www.blocklayer.com/RiseRun.aspx

enter the blade height as the "run"
enter a sharpening angle.
click "calculate"
the "Rise" is the elevation of the spine of the blade above the stone, for that particular knife

I think this calculator was designed for brick-laying, but numbers are numbers. It's all just trigonometry.


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## TB_London (Nov 6, 2013)

split0101 said:


> I don't think so. I looked around but could not find a complete reference. When I wanted to sharpen my Carter for the first time I looked around the forum to see how guys sharpen white #1.
> 
> I think having a "general" guide/table would be very useful, especially to the novice/intermediate sharpener.




I think this would be a massive case of false assurance though. 

The knife comes with a bevel, after you've used it for a bit have a look at it and think.

How did the knife perform? Did it cut how you wanted it to? 

IF YES: 
maintain the same geometry, it's working

IF NO: 
Were you getting too much wedging? If yes Thin it, 
Has the edge failed quickly from chipping / rolling? If yes increase the angle to give a more robust edge
Did the edge not have enough bite? If yes drop back to lower grit for a few strokes once you have deburred to give a more toothy edge
Do you want to see how far you can push the edge angle? If yes lower the angle and use it again, continue this reduce and use cycle until the edge fails too quickly and then increase it slightly back to the sweet spot.

Etc,

Follow a relative position of higher and lower angle from where it is now. The number doesn't matter

There are too many other variables to give a specific angle, and that angle will always be what works for someone else not you. What do you cut, what's your cutting style,how much force do you apply, do you prefer edge retention for the sake of ultimate sharpness, or ultimate sharpness for the sake of retention, what knife is it, how was it heat treated, what's the geometry of the knife like. And on and on and on


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## Ruso (Nov 6, 2013)

What TB_London says +3. There is no rule on the angle, there is to many factors why you might want to use higher or lower one.

The rule of thumb is, if it is too chippy for you, raise the angle


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## stevenn21 (Nov 6, 2013)

i am sharpening my ziganof i dont dare try on my carter yet.

ill try the sharpie trick with 1cm and see how it goes i think the ziganof maybe vg 10 but its advertised as Damascus it has a slight chip in it and my knife has some small scratches on the side so i think my angle is too small for the ziganof should i take it back to the begining and start over with the angle?

can i polish the scratches off the side i only ask because i did the secondary edge of one of my cheap supermarket knives and it would not polish up it was left with loads of scratches on the side even after i went up to a 10,000 grit whetstone.

how do i get that chip out?


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## Benuser (Nov 6, 2013)

How large is that chip? A photo perhaps?


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## jgraeff (Nov 6, 2013)

i use to worry about angles as well, but its not necessary. The most important thing is to remain consistent from heel to tip. I would use the sharpie, to color in bevel in one color and the area above in another. that way you can see where your hitting. the lower the angle the higher up the blade face you will go. I would start higher than you think and go from there slowly checking often. once you are hitting where you want keep that angle and continue until you raise an even burr along the edge. Then flip and repeat. 

To remove burr, to heel to tip sweep of existing angle, then what we call stropping which is just reverse instead of edge leading you will do edge trailing strokes with very light pressure a few times. I like wood, felt, or cork to then slice through to remove any extra burr. 

A way to find the existing bevel that has help me is the put the knife on the stone, use your nail to flick the edge, if you hit it, your angle is too low, raise the knife up and its just about flush. so you nail will slide from the stone right onto the knife without a gap. 

You can also push the knife a bit, if it digs into the stone your slightly too high, back off a notch and thats your angle. Either way are fast and efficient.


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## bahamaroot (Nov 6, 2013)

Never used a guide, never worried about an angle and have damn sharp knives. All it takes is a little practice. It's not rocket science.


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## daveb (Nov 6, 2013)

Depends on the distance from "edge" to "spine" and desired scary angle, presumably between 20 and 10 degrees.

Chad Ward presents a simple discussion of angles, how to measure, etc in his "Edge in the Kitchen". He also has much of the same material on a web site (egullet?) that will provide good fundementals.

That said, the posters above (esp TB) have provided the advanced course. It took awhile to sink in for me but I finally got that a consistent angle is much more important than a specific angle.


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## stevenn21 (Nov 6, 2013)

Benuser said:


> How large is that chip? A photo perhaps?



the chip is very slight you struggle to see it its very small but would like to remove it i doubt a photo would even show the chip


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## stevenn21 (Nov 6, 2013)

bahamaroot said:


> Never used a guide, never worried about an angle and have damn sharp knives. All it takes is a little practice. It's not rocket science.


lucky you i can get it sharpish but not as sharp as i would like


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## stevenn21 (Nov 6, 2013)

Hbeernink said:


> yup- sure can. if (t) is the angle where you want the blade to be sharpened, AB is the distance to raise the spine (from the surface of the stone), and BC is the height of the blade (heel to spine at each individual point along the blade - note that this will change as blades are not a constant height...), then:
> 
> AB = BC * sin(t)



thats a fine equation you have there bit too advanced for me though


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## bahamaroot (Nov 6, 2013)

stevenn21 said:


> lucky you i can get it sharpish but not as sharp as i would like


Give it a little time and practice and you will.


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## stevenn21 (Nov 6, 2013)

jgraeff said:


> i use to worry about angles as well, but its not necessary. The most important thing is to remain consistent from heel to tip. I would use the sharpie, to color in bevel in one color and the area above in another. that way you can see where your hitting. the lower the angle the higher up the blade face you will go. I would start higher than you think and go from there slowly checking often. once you are hitting where you want keep that angle and continue until you raise an even burr along the edge. Then flip and repeat.
> 
> To remove burr, to heel to tip sweep of existing angle, then what we call stropping which is just reverse instead of edge leading you will do edge trailing strokes with very light pressure a few times. I like wood, felt, or cork to then slice through to remove any extra burr.
> 
> ...



ill try it


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## Benuser (Nov 6, 2013)

stevenn21 said:


> the chip is very slight you struggle to see it its very small but would like to remove it i doubt a photo would even show the chip


Microchipping is very common with brand new blades. I guess it has to do with buffering in factory. You should get them out in one or a few sharpening sessions. No special action required unless you're a fanatic ceramic rod user. In that case full removal is imperative to avoid further damage and unnecessary material loss.


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## Benuser (Nov 6, 2013)

As for the angles, I usually start as low as I can, raise the spine a bit until I end with a raised burr, then the same at the other side. The end result will be an edge of some 10 degree at the right side, and some 15 left.
With some blades and some usage such an edge will need a microbevel.


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## split0101 (Nov 6, 2013)

I guess I wanted to go with something more than trial and error. For example during my last sharpening session I decided to go about 10-12* on my shun. I was able to pop hairs and shred magazine paper with little effort. After about an hour of prep work on a poly board the edge was in horrible shape. It rolled on me, started to chip and overall looked like it was in a fight. 

Next time I will need to go back to 16-20* since that seems to hold up better. I don't know if that is because its a shun or if that's because VG10 should not be pushed that steep. 

At the same time I put the same angle on my Carter but it held up much better. I still need to put it through a proper prep session on that poly board. If it does hold up dthen I'll continue sharpening it at that angle.

Next up is 51200, I'm going to go steep and see how it holds up. I have a feeling I might need to keep it in the mid-teens. Suggestions?


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## Benuser (Nov 6, 2013)

About your Shun: it has both to do with Shun and with the poly board. 
But in general I would avoid such drastic changes. I prefer finding a solution with microbevels rather than change the entire geometry and having to -- partially -- undo that again. It's a waste of material.


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## split0101 (Nov 6, 2013)

Benuser said:


> About your Shun: it has both to do with Shun and with the poly board.
> But in general I would avoid such drastic changes. I prefer finding a solution with microbevels rather than change the entire geometry and having to -- partially -- undo that again. It's a waste of material.



At the end of the day Im not to upset about it since this is a learning experience. Next time with my Shun Im going to go the micro bevel route since that should give me a more stable edge.


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## Keith Sinclair (Nov 6, 2013)

split0101 said:


> At the end of the day Im not to upset about it since this is a learning experience. Next time with my Shun Im going to go the micro bevel route since that should give me a more stable edge.



Sounds like a good plan.Trouble with Damascus blades & low shallow angles,even the stone mud can scuff up the sides of the blade.Yes you can sand out the scratches on the damascus,but the trick is not to put them there in the first place.

I like low starting angles on Gyuto's,then raise the spine & blend in a second higher bevel,when you do this you can hear the final bevel being cut in on the stone.A steady consistant spine is more important then % of angle.

On my work knives never used a Damascus blade.Start wt. shallow bevel close to the stone,then kick in final bevel.Did not care what the sides of the blade looked like as long as it was sharp & cut well.

These days sharpen Shuns alot for other people.Still start wt. shallow angle,don't let hardly any mud build up on the stone(rinse it off)Inspect your edge,even at the shallow angle should not hit the damascus line,just a little polish above the edge.It is a good idea to establish a higher final bevel as well on the Shun,it is still very sharp,good cutting edge & not as fragile.


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## Eric (Nov 6, 2013)

Just find the right angle for the primary angle by feel and sound. Use the sharpie if you can't find the bevel. Trust yourself, and listen to he sound as you gently push your blade. The slightly high pitch, different feel and confirmation with sharpi will tell you. Don't be afraid you'll only learn by doing, seeing what works and what doesn't. The height varies depending on the width of the blade, basic trig. ER


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## jer (Nov 7, 2013)

Different stones will give different feedback so it may be more difficult to feel when you are hitting the edge with some stones compared to others. If you want to try to match the existing bevel, try moving the blade in an edge leading motion on a wooden cutting board, piece of paper, etc. This will allow you to feel when the edge begins to catch, which will give you an idea of the approximate angle at what you will hit the edge during sharpening and the corresponding height of the spine.


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## stevenn21 (Nov 8, 2013)

how do i polish scratches out of a Damascus?


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## ThEoRy (Nov 8, 2013)

You have to scratch up the surface on both sides of the blade with automotive sandpaper with a grit lower than the scratch you created then progress up to the finish you would like. Or you could simply buff the blade on both sides, etch it, then buff it again. Either way it's an arduous task.


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## hobbitling (Nov 8, 2013)

Would that remove the damascus pattern, and if so, would it have to be re-etched?


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## stevenn21 (Nov 8, 2013)

hobbitling said:


> Would that remove the damascus pattern, and if so, would it have to be re-etched?


i dont think it would remove the pattern thats where the steel has been folded its not just been etched on


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## split0101 (Nov 8, 2013)

I think what you end up losing the contrast between layers but the layers are still there. However I'm only aware of damascus clad knives so I don't know how thick that layer is over the core steel. I'm not sure if you kept going with buffing that you would hit the core metal.


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## hobbitling (Nov 8, 2013)

I understand that I wouldn't remove the layers of steel (unless I drastically thinned the blade down to the core steel) My understanding was that polished damascus has very little contrast between the layers of steel. The contrast is achieved by either etching with acid, or sometimes by bead blasting, which changes the texture or color of one type of steel more than the other.


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## Justin0505 (Nov 8, 2013)

All of you forgot to account for the temperatures (ambient, steel, abrasive, and water), altitude, barometric pressure, and moon phase when writing your sharpening formulas. 
For shame. 


As for refinishing the damascus once you're all done with the maths and experimentation:
http://www.kitchenknifeforums.com/showthread.php/6474-Damascus-Knives-amp-Re-Etchng


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## Geo87 (Nov 8, 2013)

hobbitling said:


> Would that remove the damascus pattern, and if so, would it have to be re-etched?



I've recently removed a lot of scratches on a friends shun, sanding with wet & dry. It did not remove the Damascus


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## Geo87 (Nov 8, 2013)

split0101 said:


> I guess I wanted to go with something more than trial and error. For example during my last sharpening session I decided to go about 10-12* on my shun. I was able to pop hairs and shred magazine paper with little effort. After about an hour of prep work on a poly board the edge was in horrible shape. It rolled on me, started to chip and overall looked like it was in a fight.
> 
> Next time I will need to go back to 16-20* since that seems to hold up better. I don't know if that is because its a shun or if that's because VG10 should not be pushed that steep.
> 
> ...




I don't think it's a vg10 thing, more a shun thing. I used to have a shun and a few work colleagues have them, keeping it at 16 seems the best bet, with good thinning behind the edge. Although also had em at 10 degrees and it held a lot longer than you described... On poly boards. Maybe focus your efforts on the final stages on sharpening. 

I agree with everyone that said maths to determine angles is pretty unnecessary although I can see how it would appeal to some. A rough estimate with some paper plane folding skills will do the trick  many other things are more important than calculating angles to perfection ... Just my 2 cents


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## Geo87 (Nov 9, 2013)

Here's a photo, the shun on the right is one year old, quite a few scratches from diamond steel abuse

Shun on the left is 7 years old , sanded with wet and dry 400, 800, 1200 then metal polish .


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## Keith Sinclair (Nov 10, 2013)

AS mentioned auto wet dry paper.Start with finer grit see if it takes out the scratch,if not go to a lower until find grit that removes them,inspect the blade make sure they are all gone.Then go to finer grits to finish.It's not that much work as long as the scratches are lite surface ones.Be aware that you are working with a sharp edge edge,I like to wear leather gloves while doing this kind of work.


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