Heat Treating Ovens

One will do both jobs. Most shops start with a single hardening oven and temper in it afterwards, and that is a perfectly normal way to work.

A second, low-temperature oven earns its place when volume goes up. Tempering is a long hold, often repeated, so it blocks your main furnace for hours at a stretch. The HotShot HS-360T exists for exactly that at $1,288, and a Paragon Double Barrel solves it the other way by giving you two chambers in one cabinet.

The alloy decides it. Simple carbon and low-alloy steels like 1095, 5160, O1 and 52100 austenitize between roughly 1475F and 1550F. A2 and D2 sit higher, around 1750F to 1850F. The high-alloy stainless grades such as CPM-154, S30V and 440C want somewhere between 1900F and 2050F.

So a 2000F oven covers a lot of ground, a 2200F oven covers nearly all common knife steels with margin, and the 2350F Paragon ovens leave headroom for the most demanding powder metallurgy grades. Buying more temperature than you need costs money; buying less costs you a steel you cannot run.

Because tempering is a different job from hardening and does not need the same machine. The HS-360T is the same 10 x 6 x 6 inch chamber and solid state relay as their hardening ovens, rated to 600F instead of 2200F, and it costs about $400 less than the 2200F version.

Watch one limit. Some high-alloy steels, including D2 and several powder stainless grades, use a high-temperature temper near 1000F for secondary hardening. A 600F oven cannot run that cycle, so check your steel's data sheet before you commit to a dedicated tempering oven.

Two independent chambers side by side in one cabinet. The Double Barrel KM18 is 11 inches wide across 18 inches deep, which is two 5.5 inch chambers rather than one wide one, and holds 0.49 cubic feet against the single KM18's 0.24.

The practical value is running two things at once: one chamber at austenitizing temperature and one at a temper, or two steels needing different soaks. If you only ever treat one batch at a time, a single chamber at half the price does the same work.

Two things, and the second one is easy to miss. The Pro models use the Sentinel SmartTouch controller with multiple independently controlled heat zones, while the standard models are single-zone on a Sentinel TouchXpress. Multiple zones hold a more even temperature along a long chamber.

The Pro chamber is also physically bigger. The standard KM18 is 5.5 wide by 4.25 high at 0.24 cubic feet; the KM18 Pro is 6.75 wide by 5.25 high at 0.37 cubic feet. It draws 22.5 amps against the standard's 15, so it is not a like-for-like swap on the same circuit.

Yes. The Paragon KM14 and the KM18 Heat Treating Furnace both run on 120V at 14 and 15 amps and are rated to 2350F, and the HotShot HS-360K is offered in a 120V configuration at 2200F.

What 120V costs you is chamber length and ramp speed, not temperature. Every oven past about 18 inches deep on this page is 240V. See the full 120V range.

It varies more than people expect, so check the specific model rather than assuming. Paragon's Double Barrel KM18 draws 13 amps and the Double Barrel KM24 draws 18, both on a NEMA 6-20P cordset. The single-chamber KM24 is 12 amps, also 6-20P.

Step up to the Pro line and it changes: the KM18 Pro draws 22.5 amps at 5040 watts on a NEMA 6-30P, and the Double Barrel KM14 Pro draws 20 amps on the same 6-30P. Those need a different receptacle from the 6-20 models, so confirm the cordset before you have an electrician out.

Not for every steel, but they solve a real problem. At austenitizing temperature the surface of the blade loses carbon and picks up scale, which shows up as a soft skin you then have to grind away. Thin sections and high-alloy steels suffer most.

Stainless foil wrap is the usual low-cost answer. HotShot also offers an argon kit with tubing, fittings and a ceramic dispensing needle for running a protective atmosphere, though you supply the gas and regulator.

The temperature is usually there and the shape usually is not. Paragon's knife ovens are rated to 2350F, which is cone 10 territory, but a chamber 5.5 inches wide and 4.25 inches high will not take a mug, let alone a bowl.

If you want one machine for both, look at a front-loading kiln with a squarer chamber rather than a knife oven. Our ceramic kilns and glass kilns are shaped for that work.

The bench-top 120V ovens often ship by parcel carrier. The larger ones move by truck: Paragon's Double Barrel KM24 is 220 pounds and the single KM24 is 190. Freight deliveries include curbside delivery, appointment scheduling, tracking and liftgate service where required, and shipping is calculated at checkout before you buy. See our shipping page.

Performing the manufacturer's recommended initial test firing will not by itself void a return, as long as the other conditions in our policy are met. Full terms are on our returns page.