How hot does oil have to be to quench?

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.

Can I use motor oil to quench?

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.

Is it better to quench steel 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.

What kind of oil do you quench hot steel in?

Mineral and transmission oils

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.

What is the fastest quenching medium?

Brine solution gives a faster rate of cooling while air cooling has the slowest rate of cooling.

STEEL HEAT TREATING CLOSEUP - WATER VS OIL [Trollsky Knifemaking]

Can you over quench steel?

Often used to harden steels, water quenching from a temperature above the austenitic temperature will result in carbon getting trapped inside the austenitic lath. This leads to the hard and brittle martensitic stage.

What liquid do blacksmiths use to quench?

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.

What did medieval blacksmiths quench their blades in?

The smith then heats the metal so that both the iron and steel are molten and join. The blade is tempered—transformed from soft, workable metal into a hard blade—by holding the blade over a fire and then quenching the blade in a vat of oil or brine.

Does quenching make metal brittle?

Quenching results in a metal that is very hard but also brittle. Gently heating a hardened metal and allowing it to cool slowly will produce a metal that is still hard but also less brittle.

What quench oil is used on forged in fire?

As those of you who make knives know, there are several different quench oils out there, but they really fall into 2 main speeds/categories. These are fast and medium speed oils, and the most widely used products on the market are Parks 50 (fast) and AAA (medium). The best oil to use depends on the steel in question.

Why are swords quenched in oil?

The oil in the quench tank causes the steel to cool rapidly and evenly. If the steel does not cool evenly for some reason, then the blade can warp or even fracture.

What does putting red hot steel in oil do?

Hot Oils. Hot oils are always used at high temperatures and prevents temperature variations during the quenching process, which protects the metal against defects, cracks, and distortions.

Why do you preheat quench oil?

I figure preheating the oil does one of two things. It either lowers the shock for the quench, making fractures and bends less likely (hope it's this one, because it didn't happen) or it hardens better because it makes the oil less viscous, meaning it can transfer heat away from the blade better.

Can I harden mild steel?

A36 is a low carbon or mild steel, and as such cannot be hardened. It can be case-hardened, however, which just means using a chemical treatment with heat to add a thin layer of tough material around the soft steel core.

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.

Can you use engine oil to harden steel?

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.

Why do blacksmiths quench in water?

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 put hot metal in water?

Blacksmiths put metal in water because water submersion will allow the forger to control the brittleness and overall strength of the metal. This is referred to as “quenching,” and is used by many blacksmiths to decrease the risk of breakage when crafting new pieces.

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.

Why are there no titanium swords?

Titanium is not a good material for swords or any blades. Steel is far better. Titanium cannot be heat treated sufficiently to gain a good edge and will not retain edge.

Can you forge rebar?

Cons of Forging with Rebar

A first major con of using rebar for blacksmithing is its unpredictable nature. Most rebar is not made of quality metals and can even contain dangerous fumes when worked. What is this? You can never be sure what the rebar is made of, so final projects can end up brittle.

Are bronze swords sharp?

Bronze Swords

Granted, various civilizations has made sharp-bladed weapons from materials such as flint and rock prior to bronze, but the Bronze Age era set a new standard for weaponry. Swordsmiths of this era made bronze swords by mixing copper with various alloys, the most predominant alloy being tin.

Can you quench a blade in mercury?

In order to quench your sword in mercury, you need to displace more than one and a half times its own weight in mercury - and you need to put a corresponding amount of pressure on the blade. However, quenching is done while the metal is still hot and partially malleable.

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.

How long does quench oil last?

Oil Recovery

Quenching and martempering oils deteriorate during use, although most premium quenching oils can last more than 10 years when given reasonable use and care.