Coating: ATP-641, Turco, or similar high temperatureanti-scale/decarburization coatings can be used in replace of foil to reduce scale or surface decarburization.
Data is representative of controlled heat treating equipment (e.g. oven,salts, etc.) temperatures and industrial standard quenchant.
Suggested quench oil: Parks 50–expected as quenched hardness may be lower if a slower quench oil or non-industrial quench medium is used.
Austenizing: Austenizing temperature (1,450 to 1,480°F /801°C) Soak time varies 5 to 15 minutes based on heat treating equipment and cross section–soak times are reduced to minimum for people heat treating in a forge–forge heat treating without PID temperature control limits accurate means of maintaining temperature. If using calibrated, proper industrial equipment for heat treating, use the supplied extended soak times based on over all steel thickness.
**Do not put blades in oven when cold, insert at or just below austenizing temperature–temperature variances is for difference in stock thicknesses and a window of margin for error.
Tempering: Once blade is quenched and near ambient temperature, blades should be tempered accordingly, the times suggested are to ensure even, consistent temperature.Figures supplied are as representative of industrial standards.*If using a small toaster oven or household kitchen oven for tempering, using a blade holding rack made from kiln furniture, a roasting tray lined with fine sand, or similar large object will help retain thermal mass to reduce wide swinging temperatures as the device fluctuates trying to maintain temperature.
Note: Final hardness values vary based on initial as-quenched hardness and percentage of conversion to Martensite. Only reliable testing methods, e.g. calibrated Rockwell hardness tester, can provide actual hardness values–hardness calibrated files and chisels are relative testing methods and inaccurate for true hardness value reading.
Temper twice for 2hrs.
2 comments
Hi Scott,
Great question. For 1075 carbon Damascus, the quench speed matters a lot, so you want an oil that’s fast enough to harden 1075 without being so aggressive that it cracks or warps.
If you’re experimenting on a budget, the best “less expensive but still works” option is usually a lightweight, clean mineral oil (the same “white mineral oil” sold for butcher blocks). Warm it up to about 120–140°F before quenching and keep the oil volume large enough that it doesn’t heat up instantly.
A couple quick notes:
Avoid things like used motor oil or mystery oils—fumes/toxicity + inconsistent performance.
Vegetable oils (canola, etc.) can work in a pinch, but they can be inconsistent and break down faster (and can get pretty smoky). If you try it, keep it warm and understand results may vary.
If your jewelry pieces are thin, they’ll often harden more easily than thick blades, but you can still get warping—so do a few test pieces first.
I am quenching jewelry.
At the moment, I am just trying something new for me so I’m trying to do this inexpensively, is there a lesser oil I can use?