Aside from finishing, no area of woodworking these days abounds with variety as does sharpening. The notion of sharp is the common denominator. In that there is agreement: Know what sharp is, and do it.
Perhaps the advent of fractional horsepower electric motors have been responsible for the loss of the notion of sharp more than anything since the demise of the apprentice system. Think about it. If working with dull tools entails little more than pushing into an electric saw or planer, the incentive for understanding sharp and doing something about it loses its imperative. John Gardner, father of the revival in teaching how to build small wooden boats, said “when potato power gets things done, your hand tools need to work.” The imperative is fatigue and pride is the guide.
Which is harder: File Steel or Blade Steel?
Some tools are sharpened by file. Some are sharpened by grinding and polishing. All the tools which are sharpened by a file have steel, which is softer than file steel (about Rockwell 55). Trying to sharpen harder steel will ruin your file. It’s a rock-paper-scissors game. The tools that use a file for sharpening are scrapers, hand saws and chain saws.