Evenheat vs Paragon Knife Ovens: Specs, Prices, Circuits

Evenheat gives you a wider, taller chamber for less money and publishes electrical specifications that reconcile. Paragon gives you a longer chamber per dollar, a drop or side-swing door at no charge, a heat treating kit in the box, and multi-zone models Evenheat does not sell. Under 27 inches of blade, buy Evenheat.

Both are American, both have been at this since the 1980s, and both build the same machine in outline: a firebrick box with side elements, a door at bench height, and a solid state relay. The differences are narrower than the marketing suggests and more consequential than the spec sheets admit.

What do you actually get per dollar?

This is the table nobody publishes, because it requires putting one brand’s chamber next to the other’s and dividing. Evenheat’s own site lists no prices, so those come from Soul Ceramics; Paragon’s own store lists prices but no electrical specifications. Both sets were read on 2 August 2026.

Model	Chamber D x W x H (in)	Cu ft	Supply	Street price	$ per cu in	$ per inch of depth
Paragon KM14	14.5 x 5.5 x 4.25	0.20	120 V	$2,970	$8.76	$205
Evenheat KH 414	13.5 x 6.5 x 4.25	0.22	120 V	$2,632	$7.06	$195
Paragon KM18	18 x 5.5 x 4.25	0.24	120 V	$3,015	$7.17	$168
Evenheat KH 418	18 x 6.5 x 4.25	0.29	120 V	$2,688	$5.41	$149
Evenheat KO 18	18 x 9 x 5.5	0.52	240 V	$2,600	$2.92	$144
Evenheat KO 22.5	22.5 x 9 x 5.5	0.65	240 V	$2,660	$2.39	$118
Paragon KM24	24 x 5.5 x 4.25	0.33	240 V	$3,420	$6.10	$143
Evenheat KO 27	27 x 9 x 5.5	0.77	240 V	$2,924	$2.19	$108
Paragon KM36	36 x 5.5 x 4.25	0.49	240 V	$4,050	$4.81	$113
Paragon KM45	45 x 5.5 x 4.25	0.61	240 V	$4,770	$4.53	$106

Chamber volumes computed from each manufacturer’s published interior dimensions. Paragon’s own store gives a chamber height of 4.3 inches on some models and 4.25 on others; 4.25 is used throughout here because it reconciles with the cubic-foot figures Paragon publishes (24 x 5.5 x 4.25 is 0.325 cu ft against Paragon’s stated 0.33). Prices are Soul Ceramics selling prices for Evenheat and Paragon’s own selling prices, both read 2 August 2026, and both move with controller choice.

Read the two right-hand columns against each other, because they say opposite things.

Per inch of blade length, the two brands are close. A KO 27 costs $108 per inch of chamber depth and a KM45 costs $106. Nobody wins that comparison, and length is the specification most makers shop on.

Per cubic inch of chamber, Evenheat is roughly half the price. A KO 27 is $2.19 against a KM36’s $4.81. That gap has nothing to do with pricing strategy and everything to do with the shape of the hole.

Why is Evenheat’s chamber so much bigger at the same price?

Because the two companies solved the same problem differently. Paragon’s KM chamber is 5.5 inches wide and 4.25 high. Evenheat’s KO is 9 by 5.5, and the LB is 10 by 6.25.

Chamber cross-section	Area	Versus Paragon KM
Paragon KM series, 5.5 x 4.25 in	23.4 sq in	baseline
Evenheat KO series, 9 x 5.5 in	49.5 sq in	2.1x
Evenheat LB and KF series, 10 x 6.25 in	62.5 sq in	2.7x

Paragon builds a slot. Evenheat builds a box.

For one blade at a time, the slot is arguably the better engineering: less air to heat, less mass, faster recovery when the door opens. For a batch it is a hard ceiling. Nine inches of width takes three blades side by side where 5.5 inches takes one, and 5.5 inches of height clears a taller stack of foil pouches than 4.25 does.

So the honest version of the comparison is not “which is better value.” It is: are you heat treating one blade or four? If it is one, Paragon’s slot costs you nothing you will notice. If it is four, Evenheat’s box is the whole argument, and it is available for less money.

What circuit does each one need?

Here is where the two brands genuinely diverge, and not in Paragon’s favour.

A hardening plus tempering run lasts hours, so under NFPA 70 Article 100 it is a continuous load, and 210.20(A) requires the breaker to be rated at not less than 125 percent of it. Turn that around and a 20 amp branch circuit legally carries 16 amps of continuous load, no more.

Oven	Supply	Rated W	Rated A	Does W match V x A?	125% of draw	Receptacle listed
Evenheat KH 414 / KH 418	120 V	1,560	13	yes, 1,560 / 120 = 13.0	16.25 A	NEMA 5-15
Evenheat LB 18 / KO 18	240 V	3,120	13	yes, 3,120 / 240 = 13.0	16.25 A	NEMA 6-20
Evenheat LB / KO 22.5 and 27	240 V	3,600	15	yes, 3,600 / 240 = 15.0	18.75 A	NEMA 6-20
Evenheat KF series	240 V	7,200	30	yes, 7,200 / 240 = 30.0	37.5 A	NEMA 6-50
Paragon KM14	120 V	1,920	16	yes, 1,920 / 120 = 16.0	20.0 A	NEMA 5-20, dedicated
Paragon KM18	120 V	1,800 or 2,000	17	only at 2,000 W	21.25 A	NEMA 5-20, 20 A breaker
Paragon KM24	240 V	2,600	11	yes, 2,600 / 240 = 10.8	13.75 A	NEMA 6-20, 20 A breaker, 12 AWG
Paragon KM36	240 V	3,600	15	yes, 3,600 / 240 = 15.0	18.75 A	NEMA 6-20
Paragon KM45	240 V	4,560	19	yes, 4,560 / 240 = 19.0	23.75 A	NEMA 6-20, 20 A breaker

Evenheat figures from Evenheat’s own model pages. Paragon figures from dealer listings, because Paragon’s own store publishes no electrical specifications at all. The 125 percent column is NEC 210.20(A) applied to a continuous load. The final circuit is an electrician’s call, not a table’s.

Four things fall out of that.

Every Evenheat figure reconciles. Watts equals volts times amps on all four rows, exactly. That sounds like a low bar. It is the bar Paragon does not consistently clear.

The KM45 asks for 19 amps continuous on a 20 amp breaker. Two dealers publish 19 amps and 4,560 watts at 240 volts, and those agree with each other. USA Knifemaker’s spec table then names the circuit outright: NEMA 6-20P, breaker size 20. Nineteen amps of continuous load needs a breaker rated at 23.75 amps or more, so a 25 or 30 amp circuit, and a 6-20 is a 20 amp device. The draw and the circuit cannot both be right.

That is not us reading the code more strictly than Paragon does. The same dealer’s table for the KM45T Pro three-zone lists 48 amps and a 60 amp breaker, which is 125 percent to the ampere. The rule is applied on the big model and skipped on the small one.

The KM18 has the same problem, and the conflicting wattage now resolves. Kiln Frog lists 17 amps and 1,800 watts on 120 volts, which cannot both hold. USA Knifemaker lists 17 amps and 2,000 watts, and 2,000 / 120 = 16.7, so 17 amps is the real figure and 1,800 watts is the wrong one. At 17 amps continuous the breaker must be rated 21.25 amps, and USA Knifemaker lists a 20 amp breaker on a NEMA 5-20R. Second model, same gap.

The KM24 gets three different answers from three dealers. Sheffield Pottery says 11 amps and 2,600 watts, which reconciles at 10.8. Kiln Frog says 11 amps and 1,800 watts, which does not. USA Knifemaker says 8 amps and 3,600 watts, which does not either, and in the opposite direction. Where dealers disagree, believe the one whose arithmetic works, and treat the spread itself as the warning.

None of this makes a Paragon a bad oven. It makes the electrical specification something you get from Paragon in writing before you pay an electrician, rather than something you read off a product page. Our kiln electrical requirements guide has the wire and receptacle detail, and it applies here unchanged, because a knife oven is electrically a small kiln.

One more practical note on the 120 volt models. A KH 418 ships with an ordinary NEMA 5-15 plug and draws 13 amps continuously. That needs a 20 amp breaker with 12 AWG conductors on a circuit doing nothing else. The plug fits a 20 amp 5-20R receptacle, so this costs you an electrician’s visit rather than a different oven.

Why does Paragon’s own site not list amperage?

Because the site changed. Paragon’s store is live at paragonkilns.com, and it is not the site the internet remembers.

The models have been renamed. What dealers still list as the KM14T, KM18T, KM24T, KM36T and KM45T appear on Paragon’s own store as the KM14, KM18, KM24, KM36 and KM45, alongside Double Barrel, Pro two-zone and Pro three-zone variants and a KM Vertical Pro. Prices match the dealers exactly, down to the same 10 percent discount, so the dealer network is mirroring Paragon’s list.

What the manufacturer’s product pages carry is chamber dimensions, cubic feet, voltage, firebrick thickness, controller and door options. What they do not carry is amps, watts, receptacle type, maximum temperature or shipping weight. The KM14 page states plainly that no manual and no wiring diagram are available for that model.

That is worth knowing before you shop, and it reverses an assumption worth correcting: our own heat treat oven guide said in early August that Paragon’s site returned a hosting placeholder and that a 2017 archived catalogue was the newest manufacturer document reachable. The store is up. The catalogue is no longer the best source. The electrical specifications still are not published.

Which door do you want, and does it matter?

Yes, more than most spec-sheet lines, because you open this door with a blade at 1,950F in your tongs.

Evenheat: side-opening, on every current knife model. Evenheat’s own argument for it on the KO series is that a side swing keeps the superheated door out of the path between the chamber and your quench tank. The KF Extreme goes further with dual side-opening doors across a chamber up to 49.5 inches long.

Paragon: your choice, at the same price. Drop door with a counterweight handle, or side-swing. Paragon has offered both at no extra charge since the KM series began, and a drop door doubles as a small shelf to rest a fork on. It also puts a hot slab of firebrick directly below the opening, which is exactly what Evenheat designed against.

Neither is wrong. A drop door suits a shop where the quench tank sits square in front of the oven; a side door suits one where you pivot. Decide by looking at your own bench, not at a catalogue.

Both brands fit a door micro switch that cuts power to the elements the moment the door opens while the controller keeps reading temperature. That is correct behaviour and it is not optional on a machine you open at austenitising heat.

Which controller, and does either brand build its own?

Neither does, in the sense that matters. Both run touchscreen ramp-and-hold controllers with solid state relays, and both are more capable than any published steel schedule requires.

Evenheat offers TAP II, Icon, Icon+, TAP I and Rampmaster 3 across the knife line. Icon and Icon+ are built on Bartlett’s Spark and Genesis platforms, the same family that runs Skutt and L&L pottery kilns. Evenheat’s own addition is low-error Special Limits thermocouple wire, a tighter tolerance grade than standard type K, fitted across the range.

Paragon fits the Sentinel Touch Xpress as standard, with a Sentinel SmartTouch upgrade that adds a gas inlet flow meter and solenoid. Paragon also specifies special-limit thermocouple wire.

Two real differences sit under the marketing.

Only Paragon sells a multi-zone knife oven. The Pro two-zone and three-zone models trim sections of a long chamber independently, which matters when a 36 or 45 inch chamber runs cooler at the door end than at the back. Evenheat has no equivalent in the knife line. If you are buying past 30 inches of chamber, this is the strongest argument for Paragon on the page, and it costs about $1,000 over the single-zone version of the same length.

Only Paragon offers gas injection. The flow meter and solenoid let you introduce an inert atmosphere to reduce scaling and decarburisation. That is a $360 to $540 upgrade, and it partially replaces the foil pouch that both brands otherwise require. Evenheat does not sell it.

If you want the pottery-side version of the Bartlett story, our kiln controller guide covers the ecosystem in detail.

What comes in the box?

This is a genuine cost difference that neither brand’s comparison chart shows.

Paragon’s KM listings include a heat treating kit: hot gloves, a heat treating fork, firebrick supports and four knife holders, plus a built-in stand. Evenheat sells the MK2 blade fixture, which holds up to six blades, as an accessory, and the ovens ship without tongs or gloves.

Call that $150 to $250 of first-day purchases on the Evenheat side, which narrows the price gap in the first table by roughly half at the small end. It does not close it. A KO 18 at $2,600 plus a fixture and tongs still lands under a KM18 at $3,015, with a chamber more than twice the cross-section and a 240 volt supply instead of 120.

Which one holds temperature better?

Neither brand publishes a uniformity figure, so anyone who tells you the answer is guessing. What both publish is the design reasoning, and it converges.

Both use side-only elements on their current shop models, and both give the same reason: heating from the sides rather than the back wall evens out front-to-back distribution along a long chamber. Evenheat states this explicitly for the LB and KO series. Paragon describes recessed elements in machined grooves in 3 inch firebrick, which protects the coils and stores heat through the soak.

The KH 414, Evenheat’s smallest, is the exception. It uses a wrap-around element including the back wall, which Evenheat presents as a feature of the smallest footprint rather than of the design generally. The KH 418 next to it is side-only. That is a real detail to know if you are choosing between the two smallest ovens, and it is on Evenheat’s own page.

Firebrick thickness: Paragon states 3 inches across the KM line. Evenheat’s KO series is described by Soul Ceramics as 3 inch brick against 2.5 inch on the rest of the range, which is the KO’s stated reason for a 2,350F ceiling where the LB and KF stop at 2,200F.

Practically, 2,200F clears every steel in common knife use. CPM 154 tops out at 2,000F and the powder stainless grades sit below 2,200F. The KO’s extra 150 degrees buys margin, not capability.

What do they cost to run?

Almost nothing, and the difference between them is smaller than the difference between two electricity bills in different states.

Elements cycle rather than running flat out, so the figures below use a 50 percent average duty cycle, the same basis as the rest of this site, at the EIA’s US average residential rate of 18.44 cents per kilowatt hour for May 2026. A cycle is a two hour hardening run plus a four hour double temper.

Oven	Rated kW	Harden, 2 hr	Double temper, 4 hr	Full cycle
Paragon KM18	1.80	$0.33	$0.66	$1.00
Evenheat KH 418	1.56	$0.29	$0.58	$0.87
Paragon KM14	1.92	$0.35	$0.71	$1.06
Paragon KM24	2.60	$0.48	$0.96	$1.44
Evenheat KO 18	3.12	$0.58	$1.15	$1.73
Evenheat KO 27	3.60	$0.66	$1.33	$1.99
Paragon KM45	4.56	$0.84	$1.68	$2.52

The tempering column is an upper bound. At 400F the elements duty-cycle far below 50 percent, so real tempering cost runs under these figures.

Two dollars a cycle, worst case on this table. Over 200 cycles that is $400, against a purchase price difference between comparable models of $300 to $400. So running cost never decides this, and anyone selling you an oven on efficiency is selling you a rounding error. The cost to fire a kiln page works the same method through the pottery side if you want the full arithmetic.

Warranty, and the part nobody reads

Evenheat: 2 years, per Soul Ceramics’ listings across the knife range.

Paragon: 1 year limited, stated on every dealer listing, with an extended protection plan offered as a paid add-on.

On a machine expected to run for fifteen years neither covers the productive life, and elements are a wear item under both. But two years against one is a real difference in early-failure coverage, and it points the same direction as the price table.

Who should buy which

Buy Evenheat if your blades are under 27 inches. A KO 18 at $2,600 has twice the chamber cross-section of any Paragon KM, costs less than the KM18 it competes with, runs on 240 volts instead of 120, carries a two year warranty against one, and publishes electrical specifications that add up. That is four separate arguments pointing the same way. The KO 27 at $2,924 extends it to the longest blade most shops will ever make.

Buy Paragon if you need length, zones, or gas. Past 27 inches Evenheat’s only answer is the KF Extreme, which is a 30 amp machine on a NEMA 6-50 and a different circuit project. Paragon runs to 45 inches on a 20 amp supply, and it is the only brand of the two selling multi-zone control for a long chamber or an inert-gas inlet. Those are real capabilities, not catalogue padding, and they are worth the premium to the makers who need them.

Buy Paragon if the box contents matter to you. Gloves, fork, firebrick supports and four knife holders included is a genuine convenience for a first oven, and the drop-door option is the right answer for some benches.

Buy neither yet if you make four knives a year. Send them out and put the money into grinding. Both brands are worth it at the point where turnaround time has become your bottleneck, or where you are running stainless and powder grades whose 15 minute soaks at 1,950F you want under your own control. The full case for owning the process rather than renting it is in the heat treat oven guide.

If you are coming to this from ceramics and wondering whether the small kiln you already own can do the job, read the Paragon Caldera review and the Skutt FireBox review first. A Caldera reaches 2,350F and cannot be opened at that temperature with a blade in your tongs.

Whichever way you go, get the amperage in writing before you call an electrician. On one of these two brands that sentence is advice. On the other it is the difference between a 20 amp circuit and a 30 amp one.

Elements, thermocouples and relays go through Evenheat, Paragon or an authorised distributor, because those parts have to match the model, voltage and phase; our kiln parts guide explains why third-party coils are a false economy. The items in Further reading are the consumables and test gear that go with either oven. As an Amazon Associate we earn from qualifying purchases.