How do you know what angle to sharpen your knives?

[Iloveblades]

Newbie here and I own quite a few knives.Is there a way to tell what angle each one should be sharpened at?I have a Gatco sharpener and it has a guage but how do you know for sure which angle to use.Thanks

 

[Vivi]

I take a guess looking at the edge and do 2 or 3 strokes per side, then look at the edge under some light very closely. I see where I'm grinding with the stone. If you're angle is too acute, with the spine laying too close to the stones, you will only grind the shoulder of the bevel. If you grind too obtuse you will form a microbevel on the edge. It's easier to see where you're hitting the edge if you color the edge bevel in with a sharpie then do a few strokes and check the edge again.

Also with experience you can feel and hear where you're hitting when you sharpen.

 

[Hard H2O]

You can take a sharpie and mark the edge bevel. Then make a guess and try a couple of strokes. By noting where the sharpie is removed you can adjust your angle.

Which GATCO do you have? I have the Professional.

I added their extra fine and ultimate finishing hones. Then I finish with leather strops and polishing compound.

The GATCO is a great system. I have had lots of success with it.

Good luck.

 

[cj65]

I sharpen my slippies at 20 degrees with a Lansky and strop with green or white compound and shave hair quite well. It depends on what type of work you do with your knife as to what angle bevel you want/need. Lots of good stuff to learn in this forum, check out some of the other posts. It will put a slope to yer lernin curve. Welcome to the Forum!~
CJ65

 

[SPXTrader]

Hard H2O is spot on. Mark the edge, then take a few swipes at the bevel. Adjust the angle depending on where the marker is removed.

Welcome to BFC!

 

[popcornpicker]

I think that every knife is a separate entity. The geometry of the knife determines the angle.

 

[Iloveblades]

Thanks all,I'm gonna try the sharpie idea.H2O I also have the professional kit and bought the extra fine and honing stones,but I just got those about a month ago.Looks like I need a leather strop now.

 

[cj65]

I should repost that most of the knives I buy I reprofile to 20 degree angle. :foot: I am a traditional folder and slippie man. I do like the sharpie technique while I am reprofiling. I am too clumsy to free hand sharpen, but can work up a pretty good edge with Lansky and strop. As far as what angle is best question: definitely a "depends on the knife" scenario as stated previously. I also use my magnifier lens since my eyes are not as good as they used to be.:grumpy:

 

[Jeff Clark]

Cutting performance improves if you reprofile and hone your blades to low angles. I ignore the factory angles and use a belt sander to reprofile virtually all knives to under 10 degree bevel angle (20 degree edge angle if that is how you figure it). I then finish off with a microbevel at somewhere between 10 and 15 degrees. I have essentially been using this approach for 50 years. With rare exceptions this is a strong enough edge for most things that I use a knife for.

The primary exceptions are for blades made out of very poor steel which fail in ordinary use at these angles and heavy use blades where you are chopping tough material. I don't buy knives made from crummy steel anymore and I don't do much chopping so the above works for me. For a heavy use knife made with a tough but soft steel I may compromise and create a convex bevel that ends at around 15 degrees. An example of that is my throwing knife.

 

[db]

I pretty much do the same as Jeff. Try useing the lowest angle on your system and see how that works out for you. You can always put a higher angle on if you need too. Btw the first time you grind down those fat factory angles to a nice low angle is going to take some time. Stick to the coarsest hone until your sure you have both sides ground down.

 

[Hard H2O]

Cutting performance improves if you reprofile and hone your blades to low angles.

I have found this to be true. Even cheap knives seem to be able to support lower angles than those applied at the factory.

The sharpie method will tell you what angle currently exists.

Reprofile and use of a blade will tell you what angle the steel, heat treat and grind can support and utilize best.

My kitchen cutlery is sharpened as low as I can get.

You are in charge. The factory isn't going to come and take them away. Sharpening normally does not void the warranty. If the angle doesn't work or the blade chips or otherwise can't support it then you can always resharpen to a higher angle.

 

[Jeff Clark]

I guess that I should add a warning about what constitutes "crummy" steel. There are many respected alloys that commonly have large carbide granularity to their grain structure. These hard carbides resist wear, but they make it hard to microbevel your edge to a very low angle. In a sense the steel is too lumpy. On those alloys you may want to use a wider microbevel honed at 15 degrees or higher. A classic example of this can be 440A, 440B and 440C. If these are not carefully heat treated (such as cryo treatment) you will find it best if you finish these edges less acutely. My rule of thumb is to start off going for a low angle razor edge and retreat to a more obtuse microbevel if the steel refuses to get as sharp as I prefer. I also switch over to using an extra-fine diamond hone for my finishing step on these troublesome alloys. Usually I prefer something like AUS8 alloy which does not have this problem.

 

[Blues]

Good point,Jeff. I've found that to be the case with a few 440C knives I've owned.