JMR, It's a matter of being in control of your heat source, whether it is an oven or a forge. YOU/our judgement, have to be within a range of tolerance for the steel you're using. Many a knife blade has been thermocycled using a forge as the heat source. The maker has to recognize the temperatures based on the color of the blade. A magnet helps too. The most important equipment is your brain. Get a good understanding of the way it works and you can do a lot with very little.