You can but it but it stupidly expensive.

Bright hardening is applied to certain tool or stainless steel parts where heating is in an inert atmosphere and quenching to full hardness is not necessary.

Be prompt about it. The correct hardness depends on the application of the steel being treated. I am from the UK, so 40°c is the temperature I was taught as a journeyman Smith.

Quenching is the process of rapid cooling after heat treatment of a workpiece, while tempering is a process which involves heat treating to increase the toughness of iron-based alloys. Knives need to be hard enough to hold an sharp edge through continuous mechanical abrasion, yet be soft (flexible) enough to stand up to forceful use without breaking. It requires a quenched material, quenching being as described above, be taken to temperatures below the first transformation temperature of that specific alloy (normally 1100-1300) and held for 1 hour per inch of material. If all went well, the file should feel glassy as it slides across the bevel. This is actually misleading and has to do with their use of "Tempering".

I filled the container with water and marked the water level with a red marker (see photo) where the the blade rested one third to one half its depth under the water's surface on the regulator block. The edge is the thinnest part of the blade, and therefore more prone to cracking during the quench. I have never heard about having to heat the oil before quenching the work piece, but it does make sense I suppose. I used the roughest stone I have (100 – 200 grit stone from the hardware store) to put the edge back on the blade.

For oil quenching steels. And at SST, we are highly-trained in these processes. The most important detail is that the knife enters the oil at or above critical temperature. This has to do with the metal you are using specifically. Just be careful - if any part of you gets between the blade and magnet, you can get a red hot knife stuck to your finger! The knives I have made are what I assume to be mild steel, coming from sources like hedge clippers and lawnmower blades.

IE 1" material would be kept at that temperature for 1 hour.

Some suggest buying a toaster oven for the sole purpose of knife tempering.

This seems to get off the majority of the oil, and I have never noticed a smokey smell. So my Son is 19 and has been watching forged in fire since it began. A Note on Tempering: Every article I have read on tempering gives a notice to knife makers who choose to use their kitchen's conventional oven for tempering. During quenching process, the components are held under a controlled force of a quench die of the press. Make sure you have a BC fire extinguisher (the kind that puts out grease/oil fires) nearby.

Did you make this project?