What temperature should you quench a knife at?

Step 2: Quench

(The block ensures that both sides of the blade are evenly cooled.) Many knifemakers recommend using canola oil heated to around 130℉, saying that water tends to cool the steel too quickly, which can lead to cracking, especially if the blade is on the thin side.

How hot should steel be before quenching?

Before we can start the quenching process we need to heat the steel to a high heat. We're talking extreme here- over 1,600° F. Heating to this temperature causes a grain structure called austenite to form. An austenitic grain structure produces a very soft metal.

At what temperature does a knife lose its temper?

Chuck Gedraitis Knives

About 400 deg, a straw color is where most working knives are tempered to. Anything over that and you bring down the rockwell hardness. Steralizing with a flame or cutting meat on a grill will not get it hot enough long enough to change the temper. Leaving it on the grill it will affect it.

Can you over quench a blade?

Often, after quenching, an iron or steel alloy will be excessively hard and brittle due to an overabundance of martensite. In these cases, another heat treatment technique known as tempering is performed on the quenched material in order to increase the toughness of iron-based alloys.

What oil do blacksmiths use to quench?

There are many food-grade quenching oil options available to use for blacksmithing. Among these options are vegetable, peanut, and avocado oil. Some commonly used vegetable oils are canola, olive, and palm kernel oil.

How To Heat Treat A Knife | The 4 Steps You NEED To Know

What temperature do you heat treat steel?

For the higher-alloyed tool steels processed over 2000°F (1095°C), the quench rate from about 1800°F (980°C) to below 1200°F (650°C) is critical for optimum heat-treat response and material toughness.

Can you quench a knife twice?

1) You can quench a blade many times if you are referring to the full HT. Each time erases the hardness and hamon developed in the last quench. The grain gets finer each time,so there is some benefit to a triple quench. The pattern and hardness are the result of the final quench and the subsequent tempering.

Which is better to quench in oil or water?

Water-quenched steels will generally be harder than oil-quenched steels. This is mainly because the thermal conductivity of water is higher than the thermal conductivity of most oils (that I know); consequently, the rates of cooling will be less rapid (or lower) in oils compared with water.

Why does a blade warp when quenched?

When these heated parts are quenched, their internal crystal structure changes again, and that volume change is not necessarily sufficient to offset the change upon heating. This change of volume can cause dimensional distortion.

Do you quench after tempering?

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.

Does hot water dull knives?

In addition, the heat from the drying cycle can warp your blades. DO: Hand wash your knives with warm soapy water and dry them right away. DON'T: Put wet knives away in a drawer or cutting block.

How do you harden a knife at home?

You can heat it up on your stove or use your forge to heat up a piece of rebar before plunging it into the oil to raise the temperature. For the blade to harden, it needs to cool below 900℉. Wait about 10 to 15 seconds before pulling the blade out and checking it for warping.

What do blacksmiths quench their blades in?

Blacksmiths generally use water, oil, or compressed air to quench. These substances vary in environmental impact, cost, and effects on the metal, but the best quenching medium is usually water or quenching oil.

Can you over temper steel?

While you can definitely over-temper a blade, that will leave it too soft rather than too brittle; you can also over-harden (or, rather, under-temper) it, which will leave it very hard and very brittle.

What are the disadvantages of quenching steel?

There are several impacts that should be noted about quenching a material. First, the impact on microstructure can wholly depend on the quenching process and how long it was held at certain temperatures. The percentage carbon in the steel can also impact on the time needed to obtain different forms of the steel.

Does oil quenching harden steel?

Oil quenching is a common method for hardening alloy steel forgings. It is ideal for achieving the required strength and hardness properties on many alloys.

Why are blades quenched in oil not water?

Oil has a slower rate of cooling compared to either water or brine, but faster than air, making it an intermediate quench.

Do they temper blades on forged in fire?

Contestants are given 3 hours to forge a bar into a blade profile, which then is supposed to be 'tempered' (as I will elaborate on, this is in fact quench hardening only). Sometimes they start with a fixed material not shown until they start, sometimes they can select from several types.

Can you oil quench stainless steel?

Cooling and Quenching

Martensitic stainless steels have high alloy content and, hence, high hardenability. Full hardness can be achieved through air-cooling at the austenitising temperature, but hardening larger sections may sometimes require oil quenching.

How hot should quenching oil be?

Quenching into oil above 212°F (100°C) has traditionally been referred to as "hot oil" quenching. Oil temperatures in the 195°F - 450°F (90°C - 230°C) range have been used with both ends of the spectrum normally reserved for special applications.

What is the best way to harden steel?

Steels are heated to their appropriate hardening temperature {usually between 800-900°C), held at temperature, then "quenched" (rapidly cooled), often in oil or water. This is followed by tempering (a soak at a lower temperature) which develops the final mechanical properties and relieves stresses.

What kind of oil is used to heat treat steel?

Mineral oil quenchants are excellent for oil-hardened steels and steels that require a fast quench rate. They tend to be on the expensive side, but they're highly efficient and have greater cooling capacities for steel alloys. In addition, they have a significant environmental impact since they're not biodegradable.