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Paragon Heat Treating Furnace Double Barrel KM18T - Knife Making Kiln - Paragon KM18

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This size is now out of stock but can be ordered in within 8-10 weeks. We have the KM18T single in stock (in the UK!) and available to ship.

Heat treatment for the knife maker

Great knives are more than steel and ornament. They should feel like an extension of the hand. Touch a great knife, and it feels alive. As the knife ages, its spirit remains as vibrant as the day the maker gave the knife to the world. The spirit in their knives lives on long after the master craftsmen who made them.

Test heat treating formulas

Owning a furnace means you can revel in testing different heat treatments for your blades. With a KM-series furnace you can try exotic heat treating methods at your leisure. Does quenching in dry ice improve blade performance? What happens when 52100 steel is triple-quenched with a one-day wait between each quench? After this treatment, will a 52100 blade bend to 90° without chipping? Then straighten the blade, fit a handle and test it in the real world!

With a Paragon furnace in your shop, all questions about heat treating formulas are settled. Heat treating is no longer theory. You find out for yourself what works. Testing and heat treating is at the heart of the knife making adventure. Here is where your confidence as a knife maker takes root. Through heat treating, you can master a tool steel and make it your own.

Experiment with differential hardening, an ancient blade smith technique. Try out the newest tool steels. Are they really as good as the tried and true D2 and A2?

The KM18 knife making furnace goes up to 1287°C, allowing you to experiment widely. The digital controller removes any guesswork. No longer do you need to estimate a temperature by the colour of the heat or steel, instead you just program a temperature. And no longer will you have to adjust a switch to maintain the hold time for case hardening; the controller maintains the hold time for you. You just set the hold time for as long as necessary.


The drop door opens downward with one-handed operation. A counter-weight handle holds the door securely closed. The door is mounted on a heavy-duty 1/2” thick hinge shaft for smooth opening. Because of the rigid case and heavy hinge, the door is sturdy enough for years of faithful service.

The door’s safety switch shuts off the power to the elements when it is opened, but you can still see the temperature on the controller readout. 

Superior heat distribution

To improve the heat distribution in the Double Barrel 18T, Paragon has added heating elements in the top and removed the heat from the back. The furnace heats from three directions for uniform heating; the two sidewalls and the top.

Solid furnace construction

The furnace is insulated with 3” thick refractory firebrick, which is 1/2” thicker than the standard. The sidewall elements are mounted in dropped, recessed grooves which are machined into the firebrick. This protects the element for long life and low maintenance. The elements in the top are seated in pinless element grooves.

The firing chamber is protected by a rigid steel case. A built-in solid stand lifts the firing chamber safely off your worktable. The thermocouple wire is kept inside the case for protection from the harsh environment of the typical bladesmith shop.

Internal measurements (furnace firing chamber): 

  • Volume 13.59 litre (0.48 cu.ft.)
  • Width 279 mm
  • Height 108 mm
  • Depth of 457 mm

External measurements:

  • Width 508 mm
  • Height 457mm
  • Depth 813 mm

Long lasting solid state relay

The Double Barrel 18T has a solid state relay, but also includes a fall-back mechanical relay as part of a safety circuit.

What are the benefits of a solid state relay:

  • With no moving parts to wear out it lasts far longer than a standard mechanical relay.
  • It is quiet, you will only hear the reassuring hum of elements!
  • The solid state relay makes heating elements last longer and offers better temperature control during holds.

The drop door opens downward with one-handed operation. A counter-weight handle holds the door securely closed. The door, whether drop or side-swing, is mounted on a heavy-duty 1/2” thick hinge shaft for smooth opening. Because of the rigid case and heavy hinge, the door is sturdy enough for years of faithful service.

Printed instruction manuals

Your furnace includes a wiring diagram, a controller instruction manual, and a heat treating manual with heat treating instructions for D2, 440C, ATS 34 and 154 CM. The manuals are written in plain English for the beginner.

Online manuals can be found here:
CONTROLLER - 12 Key Sentry 3.0


Some feedback from happy Paragon furnace users:

“Paragon offered me no financial rewards or free equipment for this endorsement. I recommend Paragon furnaces only because they make an excellent, reliable product. I've made knives off and on since the sixth grade. I enjoy every second in the shop making knives. I used to harden and temper with a torch. As my skills increased, my testing of knives revealed the benefit of longer and more uniform soak times during the annealing and tempering cycles than were possible with a torch.

I finally bought a Paragon furnace. It is extremely beneficial to bladesmithing, because it allows us to do things with our blades we couldn't do otherwise. If I had known how good they are, I would have bought one years before I did.

You don't want to introduce any variables into your blades by accident, and temperature is one such variable. With a Paragon, you know exactly what causes what and why. My advice to beginning knifemakers is to use the best equipment you can as soon as you can add it to your shop. I wasted a lot of time and energy trying to make knives with less than the best equipment for the job. Invest in quality equipment, learn how to use it right, and use your time seeking the best knife you can make.

Without my Paragon oven, I would have never made the discoveries about steel that I’ve made. I love my Paragon. That Paragon sure made a big difference in my knife making. Any experiment I want to run is right there. If I want to change a heat treatment, I know exactly how. With every knife, I learn more.

Thermal cycles, commonly known as heat treating of blades, are the most significant single aspect contributing to the quality of a knifemaker’s blade. Knife makers who wish to explore the absolute frontiers of the world of knives in search of the Excalibur of their dreams must have the ability to design thermal treatments specifically intended to push their steel to the highest limits of performance. Absolute control of the temperature of their blades is absolutely essential to success.

Paragon makes a nice piece of equipment. I recommend it very highly to anyone who asks and to many people who don't ask. In order to make knives that my customers can depend upon, I have to be able to count on my equipment to provide consistent performance. My Paragon heat treating oven has always provided the degree of dependability I can count on to support my commitment to provide my customers the best functional knife possible.

Believe me, I'm much richer knowing I'm making the best knife I can. I'm much happier with myself."

Ed Fowler—explorer, author, and founder of High Endurance Performance Knife Association


“On the show, ‘Forged in Fire,’ we make weapons in a very compressed time frame. The Paragon furnace has been a game changer. It’s saved me an amazing amount of time.

Not only is the kiln wonderful and reliable, but Paragon’s service is fantastic. You can get someone on the phone and they will walk you through the problem. While moving my kiln around, it got bumped into some camera equipment, and parts on the kiln got dinged up. Within a couple of days they shipped new parts to me, and I was back to work.

If you’re making knives professionally, time is money. If your hands aren’t working, you’re not making money. So having the ability to program a kiln, let it do its thing, and literally walk away and do other work is a game changer.

Bottom line, the Paragon kiln is a good, solid product that winds up saving me a lot of time.”

David Baker, Judge on the 'Forged in Fire' TV show