Rockwell hardness

[John Powers]

I keep seeing the two steels. the regular and the rockwell hard steel. the regular is easier to sharpen, dulls faster. the rockwell hard steel is harder to sharpen but holds edge longer. I have some old Bucks and a Swan that get sharp. I guess they'd dull faster if I got to use them more. My question is just how much harder is it to sharpen the harder steel. A "few swipes" like Jamestown Distrbutors says about their two cherries set or something more?

[Cecil Arnold]

John,

All steels can be hardness tested. The scale used is normally the Rockwell "C" scale, followed by the hardness number. A good range for hand tools (knives, chisels, etc) would be Rc 58 or so. In turning tools we may go to Rc 61-63 since most turning tools are sharpened on a grinder and not to the smoothness you would use on a knife type blade. The lower the number, the easier the steel will be to put an edge on, unfortunately a low number steel will not hold that edge very well. High number steels will take an edge, require a lot of work to get the edge on, and will hold it a long time. Unfortunately high number steels are brittle and tent to chip. It's all about compromise, finding the right hardness for the task.

[Bruce Page]

Cecil is exactly right. “Rockwell” is simply a test method for checking a metal’s hardness. There are other test ranges/scales as well such as Brinell, Vickers and Durometer that test the hardness of aluminums, plastics, rubbers etc.

[Michael Fross]

Cecil is exactly right. “Rockwell” is simply a test method for checking a metal’s hardness. There are other test ranges/scales as well such as Brinell, Vickers and Durometer that test the hardness of aluminums, plastics, rubbers etc.

It's been awhile, but if I recall, the tests drop a heavy weight onto a small point on the steel from a set distance. The size of the dent is the hardness with small dents being harder material.

Michael