Now that your blade is nice and hard, it can get very sharp. However, it can also break very easily, so it is of no use. The next step in heat treating is tempering. Tempering is to ease the stress in the steel a little, so that it becomes a little less hard, but a lot tougher.
For knives, you generally want to temper them at about 425 degrees F. After hardening, sand off the scale, and toss it into you oven/toaster oven. Personally I use a toaster over because its cheaper to run on electricity than gas, but to each his own. I do two, one hour cycles at 425 degrees fahrenheit. After the first hour, you take it out and let it cool down to room temperature on its own. DO NOT COOL IT OFF WITH WATER. The temperature must be brought down gradually. Once its cool again, toss it right back in the oven/toaster oven to finish off your heat treatment.
Now that your blade is heat treated, you want to take off your work gloves when grinding the final bevel. If it heats up past 400 degrees it will turn a different color, and completely ruin the temper. With your gloves off, you know when it's too hot.
For knives, you generally want to temper them at about 425 degrees F. After hardening, sand off the scale, and toss it into you oven/toaster oven. Personally I use a toaster over because its cheaper to run on electricity than gas, but to each his own. I do two, one hour cycles at 425 degrees fahrenheit. After the first hour, you take it out and let it cool down to room temperature on its own. DO NOT COOL IT OFF WITH WATER. The temperature must be brought down gradually. Once its cool again, toss it right back in the oven/toaster oven to finish off your heat treatment.
Now that your blade is heat treated, you want to take off your work gloves when grinding the final bevel. If it heats up past 400 degrees it will turn a different color, and completely ruin the temper. With your gloves off, you know when it's too hot.