How sharp should an EDC knife be?

[jackh]

A straight razor needs to be super razor sharp to give a good, comfortable shave. But that very delicate edge will be destroyed by just opening an envelope. Destroyed for what it was intended for I mean. That's because it's so thin and fragile at the apex I think. So, even if a pocket knife has a thicker blade but the apex is super razor sharp the apex may be destroyed by normal EDC cutting that it leaves the knife duller than if the edge was simply very sharp without the hair whittling ability. I'm just thinking.

So what do you guys think. When you are done sharpening your EDC knife do you think a super sharp edge that will provide a clean, comfortable shave will last longer? Or, do you think an edge with a nice very sharp edge that will shave your arm pretty good will last longer? I'm thinking of edge retention between the need to re-sharpen. An edge without the thinnest of a SUPER SHARP edge may be more durable for EDC cutting tasks.

Thoughts?

[Evil D]

Combination of blade grind, edge thickness, steel, and intended use. But, generally I'd say sharp enough to push cut newsprint or phone book paper is sharp enough for me.

[Woodpuppy]

Comparing a straight razor to most edcs ignores that razors generally have a convex edge rather than microbevels. More meat behind the apex. I’m thinking I need the pm2 in 52100 and convex the edge.

[Bloke]

Good Question! I think you’ll likely get as many different answers as there are members. :)

I’ve learned over the years that edge refinement isn’t necessarily the path to sharp though undoubtedly different alloys benefit from different sharpening protocols and just as importantly what you intend to use for the knife for I think should be taken into consideration.

I’m fairly idle though and somewhat view sharpening knives like mowing the lawn so I don’t experiment very much at all but find that I can generally get and maintain my knives at what I consider sharp (push cut phone book paper etc. like D said) without going above a 600grit stone. On high carbide steels even lower and maintain them on medium grit rods on a SharpMaker.

[Pelagic]

Imo, an edc knife should be sharpened at 13-20 degrees per side, and be perfectly apex'd and deburred. Grit really doesn't matter, just depends on what you're cutting.

[tvenuto]

I think I tolerate a lower level of sharpness than most here. If I can cut cardboard without sawing, I’m good.

[vivi]

Sharper edges last longer than duller edges, period. Implying otherwise, well, you might as well say the same car will go further on half a tank of gas :rolleyes:

I keep some stones on my dresser. If my EDC won't at least scrape arm hair, it gets touched up. It only takes 30-60 seconds since I never let my EDC dull past that point. ~20 swipes on the sharpmaker whites and my Pacific Salt is popping hairs. With how quick and easy it is I see no reason to let it get so dull I'm sawing through things.

[Surfingringo]

Sharper edges last longer than duller edges, period. Implying otherwise, well, you might as well say the same car will go further on half a tank of gas :rolleyes:

I keep some stones on my dresser. If my EDC won't at least scrape arm hair, it gets touched up. It only takes 30-60 seconds since I never let my EDC dull past that point. ~20 swipes on the sharpmaker whites and my Pacific Salt is popping hairs. With how quick and easy it is I see no reason to let it get so dull I'm sawing through things.

^ This exactly

[Evil D]

Comparing a straight razor to most edcs ignores that razors generally have a convex edge rather than microbevels. More meat behind the apex. I’m thinking I need the pm2 in 52100 and convex the edge.

Straight razors are probably the absolute worst blade/edge to bring into any edge/sharpness/etc debate. It is a blade/edge type that is literally as specialized as it can possibly be for cutting one specific material and it isn't even expected to have significant edge retention to do it since they're stropped after and even during every use.

[Bodog]

A straight razor needs to be super razor sharp to give a good, comfortable shave. But that very delicate edge will be destroyed by just opening an envelope. Destroyed for what it was intended for I mean. That's because it's so thin and fragile at the apex I think. So, even if a pocket knife has a thicker blade but the apex is super razor sharp the apex may be destroyed by normal EDC cutting that it leaves the knife duller than if the edge was simply very sharp without the hair whittling ability. I'm just thinking.

So what do you guys think. When you are done sharpening your EDC knife do you think a super sharp edge that will provide a clean, comfortable shave will last longer? Or, do you think an edge with a nice very sharp edge that will shave your arm pretty good will last longer? I'm thinking of edge retention between the need to re-sharpen. An edge without the thinnest of a SUPER SHARP edge may be more durable for EDC cutting tasks.

Thoughts?

A 15 degree per side knife with an apex thickness the same as a razor blade sharpened at 15 degrees per side will both be as sharp as each other if finished equally. Knives with thinner bevels and primary grinds will stay sharper longer as there's less stress on the edge. That's not saying thinner is always better, just saying that an equal edge is an equal edge. Geometry of the primary grind is what changes things quite a bit.

That and most razor blades aren't designed to stay sharp as long as possible. They're designed for efficient cutting, ease of manufacture, etc., as much as staying sharp. Knifemakers have different criteria.

[Bloke]

Sharper edges last longer than duller edges, period.

I respectfully disagree Vivi.

I’m inclined to believe a dull edge will last forever and a day (though not serviceable) and only get duller whereas a sharp edge will only last till it’s dull.

I think I know what you’re getting at but perhaps your wording is a little askew. :)

[knivesandbooks]

If I can slice phone book paper or bite the edge into my nail, I'm okay. I used to be all about have a ridiculously polished 13-15 degree edge. Now, not so much. I generally don't reprofile my spydercos right after I get them anymore. If they're sharp, they're sharp. I usually don't sharpen past 800 grit. I maintain on my sharpmaker. Eh. Crazy edges aren't a prestige thing for me anymore.

[RickC27]

Sharper edges last longer than duller edges, period. Implying otherwise, well, you might as well say the same car will go further on half a tank of gas :rolleyes:

I keep some stones on my dresser. If my EDC won't at least scrape arm hair, it gets touched up. It only takes 30-60 seconds since I never let my EDC dull past that point. ~20 swipes on the sharpmaker whites and my Pacific Salt is popping hairs. With how quick and easy it is I see no reason to let it get so dull I'm sawing through things.

^ This exactly

You guys answered it for me. I typically give a small touch up on the fine, or just ultra fine stones everyday after use. Why wait until you need to spend an hour when you can get hair shaving sharp with just a couple minutes of work. Especially when dealing with super steels.

[vivi]

Sharper edges last longer than duller edges, period.

I respectfully disagree Vivi.

I’m inclined to believe a dull edge will last forever and a day (though not serviceable) and only get duller whereas a sharp edge will only last till it’s dull.

I think I know what you’re getting at but perhaps your wording is a little askew. :)

I'm trying to see things from your perspective but what you said does not make sense to me.

If a dull edge lasts forever and a day, and a sharp edge will turn into a dull edge after use, then it would follow the previously sharp edge would also last a forever and a day.

Why would a sharp edge that got dulled last fewer cuts than a knife that began dull? I see no way for that to be possible? When a sharp knife gets dull, it still cuts, it just cuts poorly. The time it takes to get it dull in the first place is something you don't get when you start out as dull, hence longer edge holding.

[Bloke]

Sharper edges last longer than duller edges, period.

I respectfully disagree Vivi.

I’m inclined to believe a dull edge will last forever and a day (though not serviceable) and only get duller whereas a sharp edge will only last till it’s dull.

I think I know what you’re getting at but perhaps your wording is a little askew. :)

I'm trying to see things from your perspective but what you said does not make sense to me.

If a dull edge lasts forever and a day, and a sharp edge will turn into a dull edge after use, then it would follow the previously sharp edge would also last a forever and a day.

Why would a sharp edge that got dulled last fewer cuts than a knife that began dull? I see no way for that to be possible? When a sharp knife gets dull, it still cuts, it just cuts poorly. The time it takes to get it dull in the first place is something you don't get when you start out as dull, hence longer edge holding.

Fair enough! :)

I understand the point you make. :cool:

[Pelagic]

Sharper edges last longer than duller edges, period.

I respectfully disagree Vivi.

I’m inclined to believe a dull edge will last forever and a day (though not serviceable) and only get duller whereas a sharp edge will only last till it’s dull.

I think I know what you’re getting at but perhaps your wording is a little askew. :)

Lol, gotem.

[ZrowsN1s]

But what is sharp really? :D

[Pelagic]

But what is sharp really? :D

Good question! Lol

[bearfacedkiller]

As sharp as possible.

Once your bevels are set keeping a knife sharp doesn’t take much time as long as it doesn’t get too dull or damaged. I just touch up often, sometimes right before I pocket my knife for the day. I keep a few pocket stones in my truck too.

I am the same way with my kitchen knives. I keep a stone and a strop in the kitchen and they sometimes get a quick few passes right before they get used and I almost never have to give them a proper sharpening.

My point is that if you stay on top of it you only have to spend a minute or two each day and you can always have a shaving sharp knife on you.

[guywithopinion]

Sharper edges last longer than duller edges, period.

I respectfully disagree Vivi.

I’m inclined to believe a dull edge will last forever and a day (though not serviceable) and only get duller whereas a sharp edge will only last till it’s dull.

I think I know what you’re getting at but perhaps your wording is a little askew. :)

I'm trying to see things from your perspective but what you said does not make sense to me.

If a dull edge lasts forever and a day, and a sharp edge will turn into a dull edge after use, then it would follow the previously sharp edge would also last a forever and a day.

I believe he was being strictly logical about your wording, ignoring the intended meaning. A dull edge can be beat on and abused forever and it will still be a dull edge. In fact it will get duller. The quality that persists being its dullness. It will never stop being a dull edge.

A sharp edge will stop being sharp after some amount of use, it's defining quality being that it is sharp, something that will not persist. It will at some point stop being a sharp edge.

The fact that it will become a dull edge and still cut better than the previous one is the implied point you were making, but that isn't strictly captured in the wording you chose. I suspect it was a observation made somewhat tongue in cheek.