Cutting Performance - Initial coarse edge
- Original edge on the knife was ground by Phil himself, and was rather coarse. As he mentioned later, he never goes above 800-1200 grit on those knives. My guesstimate was that the edge was around 16°-18°. For utility use it is quite good, although eventually I've lowered to 15° per side, which is pretty much the lower limit for those types of steels. What is coarse and what isn't, varies from person to person, if you want to get precise grit numbers, and cutting medium as well. Sometimes 30 000 grit is not fine enough for some of the kitchen cutting, you might say that's coarse too :) At microscopic level, all edges are still micro saws, be it 300 grit or 100 000 grit. Here's a macro photo of the initial edge, just bear in mind that image is 40x magnification of the original edge, as you can see on this picture in normal scale the edge is just fine :)Phil did mention, how he used CPM-10V fillet knife, for scraping and cutting off excess fiberglass cloth saturated with epoxy. Very unpleasant job for any knife, as the whole thing is extremely abrasive. Yet CPM-10V and a knife as a whole, held up fine, and despite of its exceptionally high Rockwell hardness, there were no chips or nicks on the edge. Worth noticing that Phil is one of the few makers who grind really thin edges on his knives, resulting in very high cutting performance. Given the thin bevel and high hardness it was really impressive to have an edge withstand that sort of abuse.
I've used utility hunter knife with its original edge for 3, may be 4 months. Considering that I didn't have old boards with paint to work with, I had to resort to cardboard for some basic tests. Day one was to cut up bunch of old cardboard boxes which I had to throw away. Initially I was counting inches of the cut cardboard very accurately, testing the edge for free hanging newsprint cut after every 100 inches. After 1000 inches I figure out that wasn't making much sense since the knife showed no sign of dulling, so I gave up on precision and just went on with cutting. After around 1500 inches(total) the knife still did fine with newsprint. At this point, I just gave up :) And went on with other non-knify things I had to do.
Later that day, I took the hunter to the kitchen and used for food preparation. No major few hours long cutting session, but I did cut variety of foods including bread, onions, garlic, parsley, red radish, basil and meat. Obviously, some of that would benefited from dedicated kitchen knife, but this was a test for the utility hunter knife, so I went on with it. Overall, the result was more than satisfactory as far as knife cutting ability and use comfort goes. Although, compared to 1500 inches of cardboard that I've processed few hours earlier kitchen cutting was a breeze. Still, obviously, and expectedly, cuts were not as fine compared with much more refined edges on the kitchen knives. That's ok if you don't need fine cuts, but generally speaking, I myself prefer finer edges on the kitchen knives, although there was a time when I worked with ~600 grit edge kitchen knives and it was pretty good too. Novadays, I find that 3°-5° per side edges are more efficient and less demanding for the food cutting. Utility use is however a different matter.
Next day, which was Sunday, I went with some wood whittling. Since that isn't measurable, at least, I have no idea how to measure the amount of the wood whittled, so let's just say I was messing with it for approximately 20 mins. Besides whittling, I did twisting test, basically sticking the edge about 1-2 mm deep into the wood and twisting the blade sideways to check the edge strength. Even though the wood was quite dry, the edge escaped unscathed. Quite a brutal test, especially for the knife which had a very thin edge.
After that, one more newsprint slicing test which was ok and then back to cardboard. Obviously, I run out of long pieces on the first day, so I had to cut strips into smaller pieces. Extremely boring and exhausting procedure to be honest. Besides I've lost count several times. Roughly it was another 400 inches or so. Eventually the knife started giving up and when slicing though the hanging newsprint, I started seeing tearing.
Overall, the result was more than impressive. Before that, I have never had a knife that could: a) cut so efficiently; b) hold the edge so long without much of the maintenance. At that time I used stropping and ceramic stick for touchups, although later on I've learned to use coarse DMT diamond stones, or coarse whetstones. Both do work very quick, restoring the edge aggressiveness real fast.
During the first use, the edge performance was a surprise. Considering that back then, my main interest was in the area of field/combat knives, cutting efficiency was surprising, because compared to popular ¼" thick field knives, utility hunter is almost three times thinner, and on top of that behind the edge thickness on the utility hunter is about 5 or more times thinner than majority of heavy duty knives. Besides, the edge is flat ground, and the edge was quite acute. All that makes one terrific cutting machine. As for the edge holding, well CPM-10V with Phil's heat treatment at 64HRC did the trick. So far no other knife ever surpassed utility hunter in terms of edge holding and wear resistance, except for the CPM S125V steel Semi-Skinner Meadows, which has even higher Vanadium content 12.5% in CPM S125V vs. 9.75% in CPM-10V and higher hardness too, 65HRC. That's not to say CPM 10V or CPM S125V are the best steels for every situation and purposes in the world. They are designed for high wear resistance and high hardness. While that fits a lot of uses very well, those types of alloys has their limitations, especially with acute edges.
Finally, comparing slicing, or saw style cutting to push cutting, I have to say that slicing performance was much better. However, that was expected and naturally the knife with a coarse edge performs better on saw-cutting. On the other hand, even with push cutting, utility still outperformed most of the knives I have in my collection, save for the kitchen knives. Thickness and blade geometry, coupled with flat grind do the trick.
