A friend once told me my knife was “so sharp, it’s Stupid!” We jokingly called it “Stupid Sharp,” and it just kinda stuck with me.
First I choose the right steel for the job. I grind the most optimal geometry into each blade based on its intended use and design. Then I heat-treat or temper each blade to meet the demands of the intended use of the knife. Each knife is then carefully sharpened one at a time using my proven method. I don’t cut any corners when it comes to sharp.
The following is my usual process in making a knife:
1. Profile the blank (I’m currently doing only stock removal, and I don’t see that changing any time soon).
2. Drill holes for handles.
3. Clean up the surface of the blank.
4. Using a belt grinder, I grind the main bevels by progressing from a 36 grit belt to a 220 grit belt.
5. Carefully wrap the knife in stainless foil and triple fold the edges.
6. Heat treat the knife in an oven.
7. Plate quench the knives when the critical temperature is reached. Let the knife cool to 150F, and then return knife to the oven for the first temper.
9. Remove knife, and let cool to room temperature.
10. Dip in liquid nitrogen filled cryo tank over night.
11. Finish second and third temper.
12. Clean up flats and ricasso from 80 to 120 grit.
13. Regrind the main bevel from 80 grit to 220 grit.
14. Roughly sharpen a V edge with a 120 grit, and refine edge up to a 320 grit.
15. Frosty satin the entire knife, etch logo and clean up the etch, clean up the spine and bevel the corners for a smooth spine.
16. Tape up the entire knife blade and ricasso, then clamp the blade tang to whatever handle material I’m using.
17. Drill holes into handle material using the clamped tang as a template, and scribe outline of the tang onto handle material.
18. Rough cut the handles on a bandsaw.
19. Pin and clamp handle set together and clean up the front of the handle slabs on the grinder.
20. Temporarily pin and glue the handle scales onto the tang, remove pins and shape the handle scales on the grinder.
21. Hand sand the handle scales to smooth out contours and finish.
22. Countersink the handle material.
23. Cut rivet tubing (oversize) with a hacksaw and grind tubing to size.
24. Flare tubing.
25. Grind entire spine one last time to clean up spine and ensure that the handle scales are flush with the tang.
26. Remove tape and apply Stupid Sharp edge (discussed further below).
27. Clean entire knife with Simple Green, and pat dry. That’s all there is to it, now the Stupid Sharp Knife is done!
The answer here is edge geometry. Effective and efficient knife performance absolutely depends on how well the geometry of a blade’s edge matches the task in which the knife will be employed. Edge geometry is a combination of both primary and secondary bevels. The primary bevel/grind forms the transition from the spine of the blade to the edge. Primary bevels are typically flat, hollow, convex, chisel, and/or a combination. Secondary bevels form the edge itself. These bevels are typically either V or convex. I prefer a convex edge to a V edge because I feel the convex edge is stronger, cuts better, and is easier to maintain. While both of these bevels should be appropriate for the knife’s intended use, how smoothly a primary bevel transitions into a secondary bevel is also a critical factor underlying cutting performance.
There is no single perfect geometry that can be used in all applications. This is why matching the geometry to the task is crucial in getting the highest performance possible out of a knife. For instance, on a chopper, I generally prefer a robust full convex geometry (full convex grind into polished zero convex secondary) or full flat geometry (full flat primary into a polished zero convex secondary). On medium-sized knives that might see a variety of uses, I generally prefer a gentle convex or full flat primary into a polished zero convex edge. On small knives, I often prefer a chisel grind that also transitions into a polished zero convex edge. But there are no hard and fast rules, and I have been known to experiment with geometry to test out performance characteristics.