Sage-Tips

Can you temper steel in oil?

Tempering is most often performed on steel that has been heated above its upper critical (A3) temperature and then quickly cooled, in a process called quenching, using methods such as immersing the hot steel in water, oil, or forced-air.

What kind of oil is used for tempering steel?

Mineral Oil Oil is a third traditional quenching agent, suitable for high-speed steels and oil-hardened steels, and in fact for any steel for which the required degree of hardness is achievable. Oil has a slower rate of cooling compared to either water or brine, but faster than air, making it an intermediate quench.

Why do you temper steel in oil?

Oil has a much higher boiling point than water. The metals do not reach the convection phase until the oil reaches 450 degrees or more. Metal treated in this way cool rapidly and evenly. This reduces the risks of cracking, distortions, and uneven soft spots.

What does quenching steel in oil do?

In materials science, quenching is the rapid cooling of a workpiece in water, oil or air to obtain certain material properties. A type of heat treating, quenching prevents undesired low-temperature processes, such as phase transformations, from occurring.

Why do blacksmiths quench in oil?

Hot oils are kept at much higher temperatures and are used to ensure that a part’s core temperature and surface temperature do not vary too greatly during a quench. This controls distortion and reduces the risk of cracking. Highly hardenable alloys quench better in hot oils.

Do you have to heat quenching oil?

Room temp should be fine as long as it’s not below 50 degrees. I believe cold quenching is normally recommended only when warping and distortion during the quench are not a concern.

Can mild steel Harden?

Mild steel can be hardened – just cold roll it. For example, take a hot-rolled 1020 steel coil and cold roll it. It will come out of the cold mill as “full hard cold rolled”. Then you would want to anneal it to soften it, then temper roll it to restore some hardness to the surface.

Can you reuse quenching oil?

This reclamation of quench oil can be done in a continuous fashion, on-site. There are two ways of doing this. First, oil can be continually cleaned to prevent the buildup of soot, scale, and oxidation by products. Using high-quality filtration systems, oil can be maintained in a nearly like-new condition.

Can you use motor oil to quench a knife?

1) Motor Oils Motor oils are a common type of quenching oil used in both blacksmithing and bladesmithing applications. New and used motor oils can be used for quenching and are both widely available. New motor oil is typically cheaper to use than commercial quenching oils.

How do you quench steel in oil?

One way to do this is to make the steel red-hot, then plunge it into motor oil. The carbon in the motor oil bonds with the top layer of red-hot steel molecules and forms a tough outer covering on the steel. One last step is necessary, however, before your hardened steel is ready to work with.

How do you harden steel with motor oil?

Hardening steel with motor oil is a way of performing what is called the case hardening of steel. Pure steel is actually too soft for many applications. In order to put a hard layer on the steel, carbon must be fused at the molecular level into the top centimeter or so of the steel.

Can I use motor oil to quench the blade?

Besides health issues, motor oil is not the right quench speed for blade steels, at least. Canola oil is cheap, non-toxic, and is a good quench for a variety of simple carbon steels such as 5160, 1084, and 80CrV2. Pre-heat to around 120 degrees before quenching. Don’t use motor oil.

What happens when you mix motor oil and steel?

The carbon in the motor oil bonds with the top layer of red-hot steel molecules and forms a tough outer covering on the steel. One last step is necessary, however, before your hardened steel is ready to work with.

What type of oil is used for quenching and tempering?

These food grade oils also tend to smell better when quenching and tempering. This can be important when doing either of these processes in an enclosed area or in your house. The two most common food grade oils used in this process are peanut and canola oil. Both of these oils have high flash points which is good for the quenching process.