12-28-2017, 04:15 PM
If you get it hot enough to see ANY color (the least would be very slightly yellow- doesn't make a big difference-1-2 points) yes, that will soften the steel. If you "blue" the tip, (or anywhere else) that is a significant reduction in hardness.
These are worst case scenarios. Normally you burn your fingers at 150°F. Nowhere near hot enough to soften (temper) the edge.
I never overheat a hardened blade by sharpening, but if you're regrinding the bevels of a hardened blade, you do need to be very careful. Like one pretty quick pass, dunk it in the water bucket quickly.
Mass of the blade makes a big difference. Pressure against the belt- big difference. Dull belt- big difference. SFPM- depends on pressure and belt condition. It will magnify the effects.
You can work harden an edge by drawing the Edge across another piece of steel, pressing hard enough that you can see the edge flex as it passes over the other piece of steel (like the handle of a vice).
This is known as the "Edge Flex" test. It's used to see how chippy vs how tough an edge is. All steel that is maxed out for hardness via tempering regimen will chip. It makes a difference how hard you're stressing the edge. When I do it, I press hard. I can easily see a "wave" traveling along the edge as it crosses the other piece of steel.
Soft steel can take a lot of edge flexing, but hard steel will chip pretty easily.
These are worst case scenarios. Normally you burn your fingers at 150°F. Nowhere near hot enough to soften (temper) the edge.
I never overheat a hardened blade by sharpening, but if you're regrinding the bevels of a hardened blade, you do need to be very careful. Like one pretty quick pass, dunk it in the water bucket quickly.
Mass of the blade makes a big difference. Pressure against the belt- big difference. Dull belt- big difference. SFPM- depends on pressure and belt condition. It will magnify the effects.
You can work harden an edge by drawing the Edge across another piece of steel, pressing hard enough that you can see the edge flex as it passes over the other piece of steel (like the handle of a vice).
This is known as the "Edge Flex" test. It's used to see how chippy vs how tough an edge is. All steel that is maxed out for hardness via tempering regimen will chip. It makes a difference how hard you're stressing the edge. When I do it, I press hard. I can easily see a "wave" traveling along the edge as it crosses the other piece of steel.
Soft steel can take a lot of edge flexing, but hard steel will chip pretty easily.