I like the balance of good edge retention at low angles, initial cutting performance and ease of resharpening. A small amount of the teeth were left on the edge of the blade, giving a pleasing grip and visually reminiscent of file work found on high end European knives. There is a slight back bevel and the included blade bevel angle is 12 degrees.
The back bevel might aid in the complex shapes—such as paring shoe soles. The blade angle is about 45 degrees. Although the blade itself was somewhat coarsely sharpened, it cut the rubber sole material quite easily when he demonstrated it.
Overall, a basic, well made knife without superflous decoration or polishing. By best, I mean they offer what I consider an optimum balance of edge retention, initial sharpness, ease of resharpening and price for a leather paring knife. The steels tested were O1, A2, Machine hacksaw blade, and T All the steels rated very good to excellent, overall. O1 is a popular, standard knife steel, which I make many styles of knives out of, and it works very well on regular, vegetable tanned goat.
A2 is a newer, high tech steel gaining favor among woodworkers, since it holds an edge longer than O1. Most large woodworker blade suppliers make both O1 and A2 versions of plane blades, so there is some personal preference involved- do you like to spend a slightly longer time sharpening A2 or sharpen more often O1. Some bookbinders also use knives made from D2- but I find the high chromium content and coarse carbide structure up to 50 microns!
Fully hardened machine hacksaw blades are traditional metal starting mid. And you would almost require a set of diamond stones to resharpen it. I shaped and sharpened all of these knives by hand to a 13 degree angle. CATRA has invented and sells many machines for sharpening and knife testing.
Although I was attempting a 13 degree angle, the edge angled measured between degrees for all of the knives when measured with a laser goniometer. I think this is the result of not being able to hold the knife angle consistently enough when sharpening and the result of stropping. There also was a general tendency for the angles to be slightly more acute. This is most likely the result of natural hand motion when sharpening, since I usually sharpen parallel to the cutting edge.
I suspect if I was in the habit of sharpening perpendicular to the cutting edge, the edge angle would be even more obtuse. This is how long the edge lasted— ie.
This is the cumulative depth of 60 cycles of cutting the test pack. Initially, A2 has a slightly slower rate of dulling, which may be an advantage, but later in the test the Hacksaw slightly surpasses it. The O1 seems to have a very constant, predictable rate of dulling- the graph is very smooth.
The T15 is incredible- even at the end it was still cutting quite deep, and each cut it still quite deep. Given all the complex variables in use, it is hard to accurately observe. Electrical tape or really wide heatshrink tubing Tools: 1. A piece of paper 2. If you are not familiar with grinders or otherwise do not know proper grinder safety, please do not attempt this and ask someone for assistance. Draw with a pen an outline of the hacksaw blade on the piece of paper.
We used a blade so dull that it was described as "polished". Choose a point shape and any details you may want. We used square cut for these illustrations. Use your hand to figure out where would be comfortable to hold from and where your thumb will go. Using the paper template, mark on the blade where you plan to cut it, and the thumb notch etc you plan to grind out.
Score the band with a file at the place s you need straight cuts. Then put the blade in a vise to hold it tightly, and use pliers to snap the blade off. We spent about 45 minutes setting up the grinder, but hopefully your grinder is ready to go.
Dull any sharpness the blade may still have. Sharpen both sides of the other edge at an angle of 15 degrees. Keep your fingers on the side opposite the grinder while you are doing so.
This should only take a few minutes once you set up the grinder. Grind out the thumb indentation. Again, keep your fingers on the side opposite the grinder while you are doing so. Use electrical tape and wrap it tightly around the dull end of the knife to make the handle.
Or, you can use some large heat shrink tubing and use that. This instructable was made at Ace Monster Toys , an awesome hackerspace in Oakland, California -- if you're in the area please stop by sometime!
Reply 7 years ago on Introduction.
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