Pros: Sharp, functional, work pretty well.
Cons: a tad short, a wee bit thick
New West Knifeworks wanted my input on some beta revisions to the Petty Utility Knife they offer. There's some angle to this picture than makes them look more different than they really are. I'm no pro in the photography, sorry.
One of the changes in these samples include a tapered tang. Both of these have the tapered tang. The tapered tang is a way to manipulate the balance point in a full tang knife. The tang tapers from the ricasso to the butt of the knife giving you all the strength of a full tang, but keeping the balance point more forward in the handle.
The other primary difference is in the thickness of the blade stock. The blade in the Cocobolo handled petty is thinner at 2.9mm and the Fusionwood petty at 3.9mm. The Cocobolo weighs 4.1 oz, the other 4.6 oz. Not surprisingly the Cocolobo petty balances a bit behind the forward rivet and the Fusionwood about 1/4 inch further back.
In heft and feel, my family all preferred the lighter Cocobolo knife. I describe the difference as the Cocobolo feeling alive in my hand, as an extension of my limb. The Fusionwood felt dense and dead in the grip to me. My daughter felt that the Fusionwood just "kept going" in the cut and she didn't have the finer control of the lighter petty. Of course, my family's preferences are tainted by the knives I normally keep in the kitchen which tend towards thin and light. Outside my family, preference tended to run correlated to body size. Petite women preferred the lighter Cocobolo where men and larger women liked the heft of the thicker Fusionwood petty.
In talking with New West, they consider them both still a little handle heavy and plan on lasering out some of the tang to move the balance point and improve overall lightness.
Initial cutting was pretty similar between the two. There seemed to be some extra drag in the Cocobolo blade that I couldn't account for visually. From visual inspection, I'd have picked the Cocobolo to cut better as it appears thinner.
I don't consider this next test particularly well controlled, but I think it helped me figure out some things. I took a piece of card stock (from an empty cornstarch box) and whacked each knife into the edge of the card stock. I used my Lee Valley peasant knife as a control whack and in other cutting as well, You can see it in the celery pic above. I tried to keep the whacks as similar as I could but this is where the consistency of this test is at its weakest. My hope was that the shape of the cut as well as the depth and deformation would help inform me about the geometry of the blade and their respective edges.
The Lee Valley blade cut the deepest with the least deformation. Then the Fusionwood and in last place was the Cocobolo. It had the shallowest gash and the most distortion around the cut in the card stock. I theorized it had a thick shoulder at the transition to the edge or perhaps a wire edge from production and I was experiencing the results.
I took both blades through a full sharpening process. I treated them both the same in an effort to keep their edges as similar as I could. The testing is to determine which differences in design are preferable, not the difference between my sharpening edge as compared to the edge from New West. Did a fair amount of testing some old carrots and ginger that were headed for the compost.
Cutting became more similar but still the Cocobolo petty trailed slightly behind the Fusionwood. I began looking for other differences that might account for this. To my eye, I detected that the Cocobolo seems to have more metal behind the edge, i.e, that it wasn't ground quite as thinly as the Fusionwood. But the Cocobolo has a little swoop at the heel taking it farther up into the blade thickness too. So the visual isn't fully conclusive though still made me wonder. And it's not a good picture either. Very tough to get the focus just right.
The slow cutting of onions continued to be the test with the most apparent drag. I theorized I was getting more "suction" of the blade against the onion as the more pronounced distal taper of the Fusionwood was helping free it from this effect.
The knives are certainly capable and perform pretty well. The differences are not pronounced, more about refinements and iterations in design. They're at home on the cutting board doing the daily tasks. The thickness of the blades comes out in cheese. A sharp cheddar shows some distress and fracture when cut. Still some wedging in a thick carrots and potatoes but much better than the Choppers I tested recently.
I dug out my digital calipers finally to see some hard numbers. The Cocobolo has a lesser distal taper thinning to about 1.7 at the drop. The Fusionwood has a more pronounced distal taper starting at about 2.6mm and thinning down to about about 1.2mm at the drop. By drop, I mean the point along the spine of the blade where it's line starts to drop quickly toward the point. The Fusionwood actually starts a bit thinner because it has a fairly radical plunge cut from it's thicker steel into the blade grind. That thinness difference is not apparent to my untrained eye and I was mentally placing the Fusionwood as handicapped by thickness, when the truth was the opposite. I was unable to get numbers I trusted trying to measure the thickness at the shoulder of the edge. I don't have a steady enough hand nor enough zoom in my sight.
Visually, I thought the Cocobolo blade was thinner and would perform better but i was tricked by what I thought I knew. In cutting in cutting performance, I like the thinner blade of the Fusionwood petty and the more pronounced distal taper (which also increases thinness at the tip). No big surprise there.
In both knives, i'd have liked another inch in length and probably another 1/4 inch in height. I occasionally bumped my knuckles with the current height. And more height lets you thin out the edge some more... The length, I occasionally felt cramped in cutting stacks of vegetables. I'd have liked to find a good cantaloupe for the test but alas, the season was past. I think this would be a good blade for prepping a thin skinned melon. The petty is at home with fruit making short work of apples, mangos, pears.
And it can carve a big pumpkin pretty well too. My daughter carved this one with a petty.