A “good” vacuum for applications like heat treatment in vacuum furnaces typically ranges from about 100 microns (0.1 Torr) down to 10 microns (0.01 Torr) or even lower, depending on the specific requirements of the material and process.

Here’s a quick breakdown of vacuum quality in microns:

• Rough Vacuum: 760,000 to 1,000 microns (1 to 760 Torr) – Typical of atmospheric and low-grade vacuum systems.
• Medium Vacuum: 1,000 to 10 microns (1 Torr to 0.01 Torr) – Suitable for some industrial processes but not high enough for sensitive heat treatment.
• High Vacuum: Below 10 microns (below 0.01 Torr) – This level is typically required in heat treatment processes for tool steels and high-speed steels, where the environment must be clean to avoid oxidation and discoloration.

For your vacuum furnace operations, achieving and maintaining a vacuum at or below 10 microns should be sufficient to prevent oxidation and ensure proper heat treatment quality.