Sharpening CTS204P at low edge angles

[vivi]

I would like to hear from members who have been using CTS204P for a while. Particularly from people who have reprofiled their CTS204P blades.

I use silly thin edges. I'm talking about half of what you're picturing in your mind right now. Here is a picture of my last Military:



Now I lost that Military years ago, and purchased a CTS204P Military to replace it.

As I do with every knife in a new blade steel, I used the factory edge angle for a few months. However, as expected, its too thick for my particular tastes and I'm ready to grind it down to the 8-10 degree per side range.

When I was researching this blade steel I remember coming across comments that CTS204P did not handle extremely acute edges very well. At least not as well as say, VG10, CPMD2, S30V etc. (Which have all performed very well for me at these angles). Unfortunately I can't locate those threads right now, but if I do I'll edit this post with the links.

So what has your experience been with CTS204P at low edge angles?

[Surfingringo]

I'm not especially gentle with my knives but I've never really had much issue with chipping. The only steel I've ever had chip on me was 204p and it was fairly significant chips both times. One came from contact with a countertop and I don't know what caused the other. That's anecdotal data at best but I wouldn't be surprised if you get some edge damage if you are using this steel at 10 dps. I know you're going to do it anyway so let us know how it goes! :D

[hoimin]

Wouldn't a low carbide steel be more preferable for silly thin edges? 52100 for instance.

[vivi]

Wouldn't a low carbide steel be more preferable for silly thin edges? 52100 for instance.

Corrosion resistance is #1 on my list of desired properties from a knife steel, otherwise that would be a very good choice. (If they made an H1 Military I would have purchased one).

Contrary to most peoples experiences I've had no issues running my high carbide blades at low angles, but I have no real experience with 204P. Even my ZDP189 Caly Jr that I reprofiled flat to the stone (Convexed, mind you) did just fine whittling hardwoods.

So based on that Surfingringo is correct :D

I know you're going to do it anyway so let us know how it goes! :D

That being said I still want to hear from others. I'll probably start off closer to 12DPS and a 15DPS microbevel and go from there.

[bh49]

I reprofiled my ZT0562CF to 12 degrees per side and micro-beveled to 40 inclusive. No problem so far.

[ejames13]

If you're going that low with your edge angles, why not just do full convex or a regrind? Just a thought.

[vivi]

If you're going that low with your edge angles, why not just do full convex or a regrind? Just a thought.

Tom Krein is out of the regrind business and I don't own the equipment to do it myself, but that is a good suggestion.

[Brock O Lee]

I do not have experience with thin 204P edges, but I have a convexed PM2 in M390. I'm not sure if it is quite as thin as your Military above, but I've been using it with a 15 dps micro bevel without issues for the last 3 years.

Do you use micro bevels Vivi? My gut feel is you need the micro bevel to stabilize the edge for the high carbide steels. I also like that the convex keeps a bit more meat above the edge compared to the V edge.

[vivi]

I do not have experience with thin 204P edges, but I have a convexed PM2 in M390. I'm not sure if it is quite as thin as your Military above, but I've been using it with a 15 dps micro bevel without issues for the last 3 years.

Do you use micro bevels Vivi? My gut feel is you need the micro bevel to stabilize the edge for the high carbide steels. I also like that the convex keeps a bit more meat above the edge compared to the V edge.

Yep, I use microbevels for all my knives. Sharpening that wide of a bevel would be quite tedious without one :)

That's a beautiful edge on your Para 2. Aren't M390 and 204P extremely similar?

[Brock O Lee]

I do not have experience with thin 204P edges, but I have a convexed PM2 in M390. I'm not sure if it is quite as thin as your Military above, but I've been using it with a 15 dps micro bevel without issues for the last 3 years.

Do you use micro bevels Vivi? My gut feel is you need the micro bevel to stabilize the edge for the high carbide steels. I also like that the convex keeps a bit more meat above the edge compared to the V edge.

Yep, I use microbevels for all my knives. Sharpening that wide of a bevel would be quite tedious without one :)

That's a beautiful edge on your Para 2. Aren't M390 and 204P extremely similar?

Thanks! Yes I understand M390 and 204P are very similar, so unless the PM process or heat treatment makes a difference, I do not think you'll see much of a difference in use.

I have a 204P Military and PM2, but both of them still has thick V-edges, and I have not used them much yet. :o

[curlyhairedboy]

Keep us updated, I've found that 204p likes a polished edge at low angles.

[hoimin]

//forum.spyderco.com/viewto ... =2&t=53572

This was a fun read.

[kwakster]

Posted this on 12-18-2014 on Bladeforums:

Spyderco Southard with CTS-204P blade, which has been in use for a few years now with a Dutch scout leader.
It has already been sharpened several times by him on stones, plus two times by me on Paper Wheels (once up to 6 micron diamond compound, and once up to 15 micron diamond, the latter performing noticeably longer for the owner)

This time the knife was reprofiled from about 30 degrees inclusive to 25 degrees inclusive with a standard Paper Wheel with 220 grit SiC, then deburred with a second Paper Wheel with 0.25 micron diamond compound.
This produces a polished semi-coarse edge with an aggressive bite, as the knife is going to be used to cut a lot of 10 mm polyprop rope in the coming weeks.
You can click the pics 2 x for a bit more detail.





------
Update i received on 01-06-2015:

The owner just informed me how the edge on his Southard is doing so far.
He had used the tip of the knife to cut open about 50 dusty/dirty cardboard boxes filled with porcelain mugs, and this resulted in blunting that tip to a point that it could only barely cut copy paper.
But according to the owner this was most likely due to the fact that the tip hit the mugs every now & then.

After all 50 boxes were opened & emptied the Southard was used to cut down each box, which he measured to be a total of about 80 meters or 262 feet of cardboard.
Afterwards the edge was still able to easily shave the hair from his legs (except about 15 mm of the tip), and the owner feels that the knife isn't due for a touch-up yet.
He also noticed that the CTS-204P steel holds this edge noticeably longer than the S30V steel in his Spyderco Sage, which he had sharpened himself and used earlier for the same job.

-----------

Some time after this (don't remember how long exactly) the owner managed to damage this 25 degree edge quite a bit while prying apart partly split logs (something he knew he shouldn't have done), to the extent that the edge had both some chips & some rolling.
When i received the knife again i resharpened it to a slightly convex 30 degrees inclusive edge on a Rubber Wheel with 230 grit diamond powder & wax, which provides for quite a coarse edge with lots of bite.
Both this edge angle & edge finish seem to work well for the owner, as the next time i received the knife back for sharpening the exact same edge was requested.
The knife is in use to this day.

[Bodog]

That's not creating creating really low edge angles with a microbevel. That's creating a low saber grind or without a microbevel it's a low scandi grind.

[ABX2011]

If you're going that low with your edge angles, why not just do full convex or a regrind? Just a thought.

Tom Krein is out of the regrind business and I don't own the equipment to do it myself, but that is a good suggestion.

Big Chris and Josh of Razor Edge Knives both do regrinds quite well.

[vivi]

Keep us updated, I've found that 204p likes a polished edge at low angles.

Will do! It will be ugly (like all my edges) but I'm sure it will cut very well :)

//forum.spyderco.com/viewto ... =2&t=53572

This was a fun read.

Thanks for the link. Reading it now!

That's not creating creating really low edge angles with a microbevel. That's creating a low saber grind or without a microbevel it's a low scandi grind.

I'd have to disagree :) I think the Military in the OP is a knife with a low edge angle by any definition. The microbevel was in the 10-12 degree per side ball park, and it was micro Scandi ground or FFG with a reprofiled edge, whatever you want to call it, it has a thin edge.

If you're going that low with your edge angles, why not just do full convex or a regrind? Just a thought.

Tom Krein is out of the regrind business and I don't own the equipment to do it myself, but that is a good suggestion.

Big Chris and Josh of Razor Edge Knives both do regrinds quite well.

Thanks for the tip! I have a few projects I wouldn't mind sending their way.

Posted this on 12-18-2014 on Bladeforums:
(Trimmed for length)

Interesting post! Thanks for going into detail on sharpening method, how the knife is being used etc. I appreciate it.

[Evil D]

If you want a thin edge and high corrosion resistance why not go with S110V? Have it reground thin and micro bevel at 30 inclusive and you're good to go.

[Bodog]

Why not just have it reground? It'd be a lot less work in the long run. I really don't understand people buying knives that are way too thick, leaving them way too thick, and trying to compensate for it like in the OP by sacrificing any kind of true benefit the steel brings. Why not just buy the cheapest steel you can get and do the same thing? Just trying to understand it. All of the expense in manufacturing (and end cost of the knife) goes to waste when the steel is subjected to what it's not meant for. I just can't really wrap my head around it. It doesn't make any sense to me crippling a blade in a steel that the buyer paid extra for when if the buyer just paid a couple of bucks to have it really thinned down they would get better results for a much longer period of time with far less fuss on the sharpening stones. And if the steel ISN'T crippled by doing that then the person could have gotten away with buying and using a knife that cost about $10.

To each his own and all that but it seems like it's done not because it makes any sense at all but because someone spread around the idea that that's what every knife should be like and people just go along with it.

I am willing to bet that the vast majority of people who can get away with exaggerated bevels like that can carry a knife that's. 005" behind the edge with a spine thickness of .100" without worrying about anything at all, swipe the blade made of any steel a couple of times against any decent sharpening stone, and get results just as good or better than trying to keep up with a knife with 8 different bevels and a final apex of the exact same angle as they'd have if they just simply had the knife reground to a more appropriate thickness.

I was taught an important lesson by a salty, old crusty guy. Just because it CAN be done doesn't mean it SHOULD be done. Just get an opinel and take it down to 6 degrees per side and call it good. Why spend $180 on a knife with a steel that's not going to perform much better (if any better) with those limitations than what an opinel can do?

[Evil D]

Well Bodog the short answer is because the internet has glorified this make believe need for a knife that can split cinder blocks and stab car doors without taking any damage, so companies have to compensate for the knuckle dragger factor and build their knives to take that kind of abuse. If you want an example of what happens when a company puts out a reasonably thin knife, read up on all the horror stories surrounded the Nilakka.

[Bodog]

Well Bodog the short answer is because the internet has glorified this make believe need for a knife that can split cinder blocks and stab car doors without taking any damage, so companies have to compensate for the knuckle dragger factor and build their knives to take that kind of abuse. If you want an example of what happens when a company puts out a reasonably thin knife, read up on all the horror stories surrounded the Nilakka.

A difference between cutting up car doors with a .500" thick blade with a 40 dps edge, using a knife designed and meant for a 15 dps edge, and a knife designed and meant for a 15 dps edge that has a 6 dps edge.

Just talking reality of steel here, not that 6 degrees per side is unreasonable. Just that whatever a blade can do at 6 dps with 20CV, it can do the same with cheap, normally throw away steel like AEBL and maybe even better. It's a matter of logic and I don't understand why someone would spend a lot of extra money on a steel like 20CV when steels meant solely for cheap utility blades can do the same.

It's a whole other topic if you leave the steels at angles most likely to show what their capabilities are. Like I said, to each his own but I don't understand it. It's like taking S110V and making a sword out of it or making high speed saws for fiberglass insulation out of AEBL. It doesn't make sense to me.

If someone simply said "I know it's unreasonable and makes no sense but I like to run more than three bevel angles at ridiculous angles and know it does no good whatsoever and on top of that I'm buying and showing off high end sprint runs with these things done, not because they work better, but only because I like it and can live with it" then ok, it doesn't affect me in the slightest and the person was honest. It bugs me seeing people say that doing things like what's in the OP is workable or sensible or anything other than slightly ridiculous done solely for personal interests.