Angle question

[proedge84]

I need to know what the best angle to keep on a hard working folder is. that is used for cutting anything from card board to wood. and what steeps to take. i own a bechmade with an ats 34 blade. please let me know.

 

[Paracelsus]

I would use something like 20 degrees per side (40 degrees inclusive). Your benchmade probably came with even wider angles which may or may not be the same.

You could keep the thick bevels if you like, or take the time to thin (reprofile) the edge bevels on a coarse stone before applying the final edge. I generally prefer an even narrower angle than 20 degrees (15 degrees per side or less) but 20 or even 25% is good compromise between strength and slicing ability.

Figure out how your knife is currently ground, make both sides the same, and then consider thinning the bevels.

 

[Crayola]

For hard use, try a 20 degree bevel and see how your edge holds up. The idea is to go as thin as you can before your edge chips out. If you are opening mail, cutting cardboard, and rarely use your knife "hard", go thinner yet.

 

[knifenerd]

I agree with the above comments. The overall 40 degree angle will give you a tough, working edge. For delicate work, in the kitchen or fileting fish, probably a 15/15 angle will work better.

 

[mgeoffriau]

Your other option would be to grind the main bevel at 15/15=30, and then finish the edge at 20/20=40. Actually, 3 or 4 steps instead of just 2 would be even better, but you get the idea. That would give you a really durable, super sharp edge.

 

[Cliff Stamp]

As mgeoffriau noted, only the very edge needs to be set at the more obtuse angle. Set the whole bevel at some acute angle. Use it for awhile until it gets damaged and then sharpen at a more obtuse angle until the chips are gone. You now have a secondary edge bevel which is durable enough to resist damage and a primary one which will increase the cutting performance.

To really find the optimal edge you would do this in stages. Grind the whole thing at 10 degrees, do some work. Correct the damage at 15 degrees, do some work. If it still gets damaged, correct the damage at 20 degrees, etc. .

Note you only need to do this process for one knife. You then take the final results as a starting point for your other knives and adjust them accordingly based on materials and intended use. The process gets faster and faster the more you do it.

-Cliff

 

[SDouglas]

While Cliff's advice is appropriate for squeezing every last drop of performance out of your blade I will offer a much simpler suggestion that has worked well on my Benchmades for a wide variety of tasks.

I use a Spyderco Sharpmaker 204 to sharpen my knives. (Read Joe Talmedge's Sharpening FAQ and use the Magic Marker to get the entire edge.)

I use the 30 Degree back bevel setting to establish my primary bevel all the way to the edge. (Magic Marker to make sure.)

For Hard use knives after establishing the 30 degree edge I use the 40 Degree setting and the white stones to provide a more robust edge that doesn't chip easily.