Shoemaker's utility knife
The knife will handle all your skiving, sole shaping, and general cutting tasks with ease. Each knife comes razor-sharp and ready to use.
German stainless steel Bohler N690, 60–61 HRC.
Total length: 250 mm
Blade edge: 100 mm
Width: 30 mm
Thickness: 2.5 mm
Sharpening angle: 20°
Finish: The knife surface is sanded and then machine-satin finished. The cutting edge is polished to a mirror shine.
Most knives have a straight edge. This one is slightly concave, lens-shaped, which makes the final sharpening easier for the shoemaker. It can be used as a skiving knife. The blade tapers toward the end and has some flexibility, allowing you to make smooth, concave cuts similar to what a skiving machine produces when assembling uppers. Some areas are inaccessible for a skiving machine, and in those cases this knife becomes extremely useful.
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If you want excellent results, you must maintain the same sharpening angle throughout the entire process. Some craftsmen sharpen such knives freehand on large stones, but this requires skill, and large stones can be quite expensive.
For this type of knife (SH-M), you should look for a knife-sharpening device available in your country, even an inexpensive one. Search for an "Apex sharpening system."
As for stones, choose the best quality you can find. I personally use Boride T2 series stones.
Also recommended: an aluminum blank with leather.
aluminum blank with leather
1. Initial geometry correction
To true the geometry of the knife, use stones in the sequence: 400 → 800 → 1500 → 2500 (the last one is optional). After that, use a leather-covered blank with polishing compound.
2. Sharpening
Start with the 400 stone and sharpen evenly until a burr forms on the opposite side. Do not break the burr off; it must grind away naturally.
Move on to stones 800, then 1500, then 2500.
With coarse stones, you can work both toward yourself and away from yourself. With fine stones (1500 and above), work only in the direction toward yourself.
By the end, the burr should disappear or barely be detectable.
After this, polish the blade on a leather strop, both sides, keeping the blade perfectly parallel to the strop.
3. Testing
Test the knife by cutting a piece of firm sole leather. This will show whether the knife is properly sharpened and will also help level micro-irregularities on the edge.
If the cut is good, repeat a light polishing on the strop and the knife is ready for work. Before each use, make a few passes on the leather strop with compound.
If the cut is poor, an error occurred at some stage. Go back to the 1500 stone (or even 800 if needed) and repeat the sharpening process.
Over time, frequent polishing on leather will slightly distort the knife geometry and increase the sharpening angle. When stropping no longer helps, the knife needs a full resharpening on stones again (return to step 1).
