ugaarguy
Member
- Joined
- Mar 19, 2006
- Messages
- 13,828
At the beginning of the month I bought a ZT 0562CF from the most recent run which uses CTS-204P blade steel. The factory edge was 20 DPS / 40 Deg. Incl. by my measurement. The factory edge was semi-polished. I'm currently spending several hours per week of my time working with an education gardening program, so my knives get some interesting real world use.
Last week I noticed that the 0562's edge wasn't cutting as aggressively as I'd like against some thick, rubbery, overwintered, and bolted onion stalks. So, over the weekend I decided to sharpen it on my Wicked Edge and take it down to a less polished, more toothy, edge by stopping at 600 grit. I also reprofiled the edge to 16 DPS / 32 Deg. Incl. The edge reprofiled easily with time and work comparable to similarly thinly ground S30V blades I've sharpened in the past. This confirms the numerous reports I'd read that Carpenter 204P (also designated M390 by Bohler) sharpens very similarly to Crucible S30V and S35VN. This is significant improvement in ease of sharpening over Uddeholm Elmax.
In use this morning harvesting stalk / shoot vegetables the knife cut much more aggressively. In use this afternoon clearing overgrown vines from a metal fence the blade felt very aggressive in cutting performance. The vines were a mix of fibrous, woody old to intermediate growth, and young, green shoots. While working in a corner of the fence I did hit a tubular steel fence post fairly hard on the follow through of a couple of cuts. One small section in the belly of the edge suffered a very small chip.
I decided to try sharpening out the chip with a field sharpener as a further test. I've misplaced my DMT 325/600 grit dual sided Diafold, so I had to use my backup, a Smith's 325/750 grit DCS4 dual sided field sharpener. The Smith's isn't bad, but my subjective experience is the DMT sharpens better, and the abrasive feels more consistently distributed within the substrate. That aside, it only took a couple of minutes to sharpen the chip out and blend the edge back to a consistent finish along the entire length of both sides of the blade.
204P / M390 is recommended by Bohler-Uddeholm corp for applications where max edge retention is the goal over toughness. B-U and the knife industry in general recommended Elmax at the same hardness or S30/35 a few points softer on the Rockwell C scale over M390 / 204P if toughness is the primary goal. So, I knew I was pushing the performance envelope sharpening a 204P blade to that acute a level. Overall I was actually very impressed that the chip was so small and limited to only one area. I was even happier when it sharpened out as quickly and as easily as it did.
My conclusions from this limited use are that 204P is tougher than I thought it would be, and it actually sharpens more easily than I thought it would. If I knew I was going to use a knife more abusively I'd either opt for a 204P/M390 blade with a thicker more conventional grind, confidently use a thin ground Elmax blade, or sacrifice a bit of edge retention for ease of sharpening with a thin ground S30/35 blade. In a few months I may have to acquire the standard G10 handle version of the 0562 with the Elmax blade and see just how far I can push that steel in a thinly ground blade.
Last week I noticed that the 0562's edge wasn't cutting as aggressively as I'd like against some thick, rubbery, overwintered, and bolted onion stalks. So, over the weekend I decided to sharpen it on my Wicked Edge and take it down to a less polished, more toothy, edge by stopping at 600 grit. I also reprofiled the edge to 16 DPS / 32 Deg. Incl. The edge reprofiled easily with time and work comparable to similarly thinly ground S30V blades I've sharpened in the past. This confirms the numerous reports I'd read that Carpenter 204P (also designated M390 by Bohler) sharpens very similarly to Crucible S30V and S35VN. This is significant improvement in ease of sharpening over Uddeholm Elmax.
In use this morning harvesting stalk / shoot vegetables the knife cut much more aggressively. In use this afternoon clearing overgrown vines from a metal fence the blade felt very aggressive in cutting performance. The vines were a mix of fibrous, woody old to intermediate growth, and young, green shoots. While working in a corner of the fence I did hit a tubular steel fence post fairly hard on the follow through of a couple of cuts. One small section in the belly of the edge suffered a very small chip.
I decided to try sharpening out the chip with a field sharpener as a further test. I've misplaced my DMT 325/600 grit dual sided Diafold, so I had to use my backup, a Smith's 325/750 grit DCS4 dual sided field sharpener. The Smith's isn't bad, but my subjective experience is the DMT sharpens better, and the abrasive feels more consistently distributed within the substrate. That aside, it only took a couple of minutes to sharpen the chip out and blend the edge back to a consistent finish along the entire length of both sides of the blade.
204P / M390 is recommended by Bohler-Uddeholm corp for applications where max edge retention is the goal over toughness. B-U and the knife industry in general recommended Elmax at the same hardness or S30/35 a few points softer on the Rockwell C scale over M390 / 204P if toughness is the primary goal. So, I knew I was pushing the performance envelope sharpening a 204P blade to that acute a level. Overall I was actually very impressed that the chip was so small and limited to only one area. I was even happier when it sharpened out as quickly and as easily as it did.
My conclusions from this limited use are that 204P is tougher than I thought it would be, and it actually sharpens more easily than I thought it would. If I knew I was going to use a knife more abusively I'd either opt for a 204P/M390 blade with a thicker more conventional grind, confidently use a thin ground Elmax blade, or sacrifice a bit of edge retention for ease of sharpening with a thin ground S30/35 blade. In a few months I may have to acquire the standard G10 handle version of the 0562 with the Elmax blade and see just how far I can push that steel in a thinly ground blade.
