To what angles do you sharpen "unknown steel" knives?

[Bolster]

I occasionally run across an old, vintage curiosity of a knife. Sometimes I rehab them and use them in the shop. When I've no idea of what kind of steel is in the knife...what's a good D.P.S. to choose? I'm leaning toward 20 D.P.S. for "unknown steel" knives but I'm open to persuasion...

[SpyderEdgeForever]

I occasionally run across an old, vintage curiosity of a knife. Sometimes I rehab them and use them in the shop. When I've no idea of what kind of steel is in the knife...what's a good D.P.S. to choose? I'm leaning toward 20 D.P.S. for "unknown steel" knives but I'm open to persuasion...

This is great info.

[horzuff]

I'd start at 15 and add microbevel IF there is unexpected damage in use. But that's what I do with basically every knife I get ^^. Rarely do I happen upon a steel that can't handle it (I had a couple D2 and M390 blades whose edges crumbled at that dps) and most can go lower still

[Ramonade]

20 too, just to see... No reason to remove a lot since unkown steel knives usually have 20 or 25 dps edges, then I see what it can handle at 20 dps. If it's very good then I'll bring that down next time :)

[Ankerson]

I just match the current edge geometry.

[SpyderEdgeForever]

Forgive me for this but while I have been a knife guy for decades and have steel and knife stuff practically memorized, my sharpeningvis extreme novice.
I usually rely on factory edges and if the edge gets devastatingly dull, I resort to those pull through sharpeners with ceramic or carbide steel heads, or a basic flat stone.
I have not purchased a Sharp Maker in all these years. Sal, please don't think badly of me for that.

My reasoning has been:
"Why should I spend that money on a Sharp Maker when for the same price I can get 1or 2 Spyderco Enduras, which Spyderco makes so wonderfully sharp that the factory edges will be fine?"

I did get one of those folding diamond plate sharpeners, a Work Sharp hand model, and some aluminum oxide rectangular stones.

I still have not gotten around to watching vivi and David's tutorials. I know those can help.

The 20 degree angle stuff interests me.

[Scandi Grind]

If I'm gonna use it, I'll try to go around 15-16 dps. If someone else is gonna use it, I go a bit sturdier and shoot for 18 dps. I have never met a knife that couldn't go to 18 dps. If it can't handle that then something is probably wrong with it so I wouldn't bother using it.

[Scandi Grind]

My reasoning has been:
"Why should I spend that money on a Sharp Maker when for the same price I can get 1or 2 Spyderco Enduras, which Spyderco makes so wonderfully sharp that the factory edges will be fine?"

Well, you only have to buy a sharpmaker once, then you can keep the same Endura sharp for the indefinite future at no additional cost! For me though the bigger deal than the money involved with buying new knives once the edge gets super dull, is that I don't want long drawn out periods where the edge isn't working at it's best. I want my knives to work very efficiently, and you can't get that without sharpening at least half a dozen times a year with my level of use. Kitchen knives I sharpen even more often.

I think the sharpmaker would be an excellent investment to get you into edge maintenance. You could always get a cheap bench stone if money is a concern, but you have to be prepared to put in the work to learn that, so the sharpmaker is probably a good way to start getting the benefits of sharpening without having to invest much time into the skill. After that you can always learn to freehand at your leisure if so inclined.

[vivi]

kitchen knives: 10-12dps

pocket knives and small fixed blades: 12-15dps

machetes and other chopping tools: 15dps

I can't think of any cutting tool off the top of my head that needed a 20dps edge to not take damage for me.

[SpyderEdgeForever]

My reasoning has been:
"Why should I spend that money on a Sharp Maker when for the same price I can get 1or 2 Spyderco Enduras, which Spyderco makes so wonderfully sharp that the factory edges will be fine?"

Well, you only have to buy a sharpmaker once, then you can keep the same Endura sharp for the indefinite future at no additional cost! For me though the bigger deal than the money involved with buying new knives once the edge gets super dull, is that I don't want long drawn out periods where the edge isn't working at it's best. I want my knives to work very efficiently, and you can't get that without sharpening at least half a dozen times a year with my level of use. Kitchen knives I sharpen even more often.

I think the sharpmaker would be an excellent investment to get you into edge maintenance. You could always get a cheap bench stone if money is a concern, but you have to be prepared to put in the work to learn that, so the sharpmaker is probably a good way to start getting the benefits of sharpening without having to invest much time into the skill. After that you can always learn to freehand at your leisure if so inclined.

Thank you! This is some of the best sharpening advice I have ever been gifted.

[Ankerson]

My reasoning has been:
"Why should I spend that money on a Sharp Maker when for the same price I can get 1or 2 Spyderco Enduras, which Spyderco makes so wonderfully sharp that the factory edges will be fine?"

Well, you only have to buy a sharpmaker once, then you can keep the same Endura sharp for the indefinite future at no additional cost! For me though the bigger deal than the money involved with buying new knives once the edge gets super dull, is that I don't want long drawn out periods where the edge isn't working at it's best. I want my knives to work very efficiently, and you can't get that without sharpening at least half a dozen times a year with my level of use. Kitchen knives I sharpen even more often.

I think the sharpmaker would be an excellent investment to get you into edge maintenance. You could always get a cheap bench stone if money is a concern, but you have to be prepared to put in the work to learn that, so the sharpmaker is probably a good way to start getting the benefits of sharpening without having to invest much time into the skill. After that you can always learn to freehand at your leisure if so inclined.

Had mine for almost 40 years now, came with a VHS Tape.

[Mage7]

I start with something obtuse like 20 or even 25 so I can see how the metal actually wears without concerning myself with deformation as much, and then I just go backwards from there because my starting obtuse and thinning down, you're only taking metal off the shoulders rather than making the blade narrower from edge to spine. Usually if I find that it keeps cutting well enough for a while at 15-20 degrees, then I will take it down to 10-15 degrees and watch for deformation, and increase the edge angle from there until it maintains stability. That way I know I have optimized it for both edge stability and edge retention, while also minimizing the amount of excessive metal removal needed to find that angle. Usually it will look a bit ugly for a while with multiple bevels on the edge, but it will even out into a single V bevel over time and it doesn't really affect the performance much.

[aicolainen]

I'd start at 15 and add microbevel IF there is unexpected damage in use. But that's what I do with basically every knife I get ^^. Rarely do I happen upon a steel that can't handle it (I had a couple D2 and M390 blades whose edges crumbled at that dps) and most can go lower still

I'm not one to give advice about sharpening, but this has been my approach as well. It's been working decently well, so I haven't felt the need to explore other protocols.

The exception are some of the cheap (mostly kitchen) knives that I keep around for abusive tasks. Don't see any benefit from investing a lot of effort to find the optimal edge on these ones, so I just touch them up with the 20 degree setting on the Ken Onion Work sharp once in a while.