Configure your custom cartridge heaters

We have many Hotrod cartridge heaters in stock for rapid delivery, but there are nearly infinite possible configurations .  Jobco provides exactly what you need.  Answer the questions below to spec your heater needs.  We’ll make sure everything is covered, then we’ll let you know the details for receiving your products.

Delivery generally takes a couple of weeks, but all our cartridge heaters are made in America.  You can expedite your custom order and we can ship in as little as one day!  You never get caught waiting for imports that may never show up.

All requested design features will be promptly reviewed by engineering, and a Jobco representative will contact you as soon as possible with any design concerns and/or your pricing information.

Backer Marathon Hotrod heaters routinely outperform other heaters.

  • Swaging process refinements
  • Specially designed cores
  • Carefully sourced MgO fill and Nichrome wire
  • The best stainless steel tubing
  • Outstanding production control

Lead wires can handle up to 550° C (1022° F).

High impact ceramic caps block contamination, protect against vibration damage, and keep the leads from fraying in bent applications.

End caps are TIG welded to keep out contamination and moisture.

HotRods are UL recognized, CSA certified, and RoHS compliant.

See below for more specifics about our custom cartridge heaters.

Sheath Options

304 Stainless Steel is suitable for temps up to 1400° F.

Incoloy can handle temps up to 1600° F.

316 Stainless Steel is most suitable for corrosive environments.

Lead Wire Options


-our standard lead wire option. Duraflex provides the highest temperature rating -550° C (1022° F).  It is durable, resists fraying, and provides good moisture resistance.


Handles temps up to 250 degrees° C (482° F)  Provides good dielectric strength

Silicone Rubber

Up to 200° C (392° F) and provides excellent moisture resistance

Braided Silicone Rubber

Inexpensive, and good choice for non-abrasive applications.

SJO Cord

Available on heaters 3/8″ in diameter and larger.  The outer rubber sheath provides good oil and moisture resistance with temperatures up to 90° C (194° F)

Swaged-in Leads

Swaged-in leads are the default configuration.  They’re great in situations with a lot of movement or where the leads have to be bent sharply just above the cartridge.
If the full length of the heater is inserted into the hole, the leads will be warmed to the full temperature of the material, and leads should not be heated beyond 550° C (1022° F).
There is a small unheated area at the end of the cartridge where the leads are connected.

Crimped-on Leads

You’ll want to use crimped-on leads where the temperature exceeds the maximum temperature of the lead materials.
Crimped-on leads are not recommended where the leads will be bent over sharply right out of the cartridge, or in applications where there will be a lot of flexing.
High temperature connectors are covered by a 1 1/2″,  2500V silicone/fiberglass sleeve.

Right Angle Leads

A stainless steel cap brings the leads out to the side, making these ideal for applications with minimal headroom.
Leads are covered with a silicone/fiberglass sleeve where they leave the heater.
When specifying, please indicate the overall length for the cartridge, including the headroom for the right angle.

Stainless Steel Braid -Straight and Right Angle

Both the leads and the braid are swaged in.  This provides exceptional protection against them being pulled out of the cartridge.
The braid provides the best protection from fraying while maintaining flexibility.
Right angle braid exits from a metal cap on the end of the cartridge.  When ordering, be sure to specify the overall length, including the cap.

Stainless Steel Flexible Conduit -Straight and Right Angle

The flexible conduit is swaged into the heater along with the leads.
This provides the best abrasion protection, but isn’t as flexible as the flexible braid.
For 1/4″ heaters, the O.D. of the conduit is .25″
For 5/16″, 3/8″, and 1/2″ heaters the O.D. is .303″
For 3/4″ and 1″ heaters, the O.D. is .48″
When ordering Right Angle, include the overall length of the heater, including the cap.

Convoluted Conduit -Straight and with Copper Elbow

This flexible stainless steel hose is brazed directly to the cartridge sheath.
Rated for temps up to 1100° F (593° C)
This conduit is flexible, but not designed for applications where regular movement is required.
Only available for heaters 1/2″ and larger.  O.D. is .50″
Static bend radius is 1″.  Dynamic bend radius is 5″
Flexible conduit can also be attached by means of a straight copper coupler.

Ceramic Beads

These beads can be added to regular leads in situations where the temperature in that area will exceed 1100° F (593° C)


Leads can be sleeved where they exit the heater for additional protection.  They can be sleeved with fiberglass over crimped leads, or silicone/fiberglass over standard leads can be applied to the leads individually or together.

Lava Seal

A swaged-in lava plug keeps contamination out of the cartridge.  Up to 1500° F (815° C)

Epoxylite Potting

Similar to epoxy potting, up to 600° F (315° C)

Epoxy Potting

Up to 265° F (129° C).  Excellent mechanical strength, but doesn’t bond well to teflon or silicone rubber leads.  Bonds well to Duraflex leads.


Protects against thicker liquids and dust, but isn’t waterproof.  It is somewhat brittle, and can crack in high impact or high vibration environments.  Up to 2600° F (1426° C)

Teflon Seal

A mechanical seal created by compressing a solid Teflon button in the end of the cartridge.  This solution generally requires a 1″ unheated section at the cartridge end to avoid overheating the Teflon.  Teflon lead wire is always used with Teflon seals.  Up to 300° F (149° C)


Good moisture seal up to 500° F (260° C).  Bonds well to silicone leads.

Single and Double End NPT Fittings -Brass and Stainless Steel

Heater Diameter:  1/4″ | 3/8″ | 1/2″ | 3/4″ | 1″

NPT Thread Size: 1/8″ | 1/4″ | 3/8″ | 3/4″ | 1″

Threads can be tapered or straight.
NPT nuts can be hex or square.

Internal Thermocouple

Thermocouples can be Type J or Type K, grounded or ungrounded, and mounted either at the bottom end or middle of the cartridge.
Thermocouple leads are solid 24 gage and the same length as the power leads unless you specify otherwise.
The defaults are grounded, with fiberglass leads.
You can specify a Type A configuration, which measures the center of the heater core at the midpoint.  A Type B is also located at the midpoint, but measures the part temperature.  Type C is at the disc end.


All flanges are 1/16″ thick stainless steel and round unless you specify otherwise.
Flanges can be welded on the lead end.
They can be used to secure the heater in place to stop it backing out.
They can also be helpful when removing the heater.

One inch flanges can be used on heaters from 1/4″ to 1/2″.
One and a half inch flanges can be used on heaters from 1/4″ to 3/4″.
Two inch flanges can be used on heaters from 1/2″ to 1″.

Mechanical Stops

A variety of mechanical stops can be applied to the sheath to prevent the heater from sinking too far into the hole.  These include weld beads, tab stops, and custom flanges.

Double-Ended Heaters

Cartridge heaters are also available as thru-circuits.  The lead enters one side, joins the heater coil, which joins the lead at the the other end.  Leads can be any type of lead wire above, straight pins, or screw terminals.  Please specify your needs in the Notes section.

Post Terminals

Cartridges 1/2″ and larger can be fitted with post terminals.  These are also known as screw or stud terminals).
Terminals have #6-32 threads, and come with 2 SS nuts and washers on each post.

Bent Cartridges

Cartridges themselves can be bent for specialized applications.  The bend can range from 10° to 120°, and must be made in an unheated section of the cartridge.
Clearly specifying the lengths and tolerances of a snap-in cartridge is beyond the scope of a simple order form.  Please call Jobco at 479-424-1300 to arrange to work with an engineer on your custom cartridge needs.

End Tube Extensions

Right Angle sheath extensions are available.  They can support and isolate leads, as well as acting as mechanical stops for the cartridge.  Specify the length of any extensions in the Notes section of the form.

Spring Guards

Spring guards are stress relievers to support leads where they exit the cartridge in situations where they are flexed regularly.

Swaging cartridges down to their specified diameter translates to some variance in the length.  Marathon manufacturing processes control for this pretty consistently, but there can be sensitive applications where more control is called for.  Unswaged heaters don’t have these length considerations.
One option is to order the cartridge short enough that if produced to the maximum tolerance, it will still stay fully within the block.  This can, however, result in a gap at the bottom of the hole if the cartridge not at the top end of the tolerances.
Another option is to specify that the heater be trimmed following swaging.  Only the unheated portion of the cartridge can be trimmed, so it may be necessary to specify a larger unheated section at the top to ensure the precise area needed is heated.  The excess cartridge is trimmed off as usual.

Marathon does offer a heater line known as HTS, which allows for the heated area of the cartridge to be adjusted.  HTS heaters are only available in a limited number of power and length configurations.  Please mention in the Notes section of the form if you would like a quote for an HTS heater.

Not 60Hz A/C

These cartridge heaters work equally well on DC power or AC circuits at frequencies other than the US standard 60Hz.  The wattage rating and performance specs remain unchanged.

Dual Voltage

Cartridges can be designed to function at two different voltages.

Three Phase

Cartridges can be used with 3-Phase power for high amp applications.  There are restrictions, so call Jobco at 479-424-1300 to arrange to discuss your options with an engineer.

Individually Controlled Heat Zones

Cartridges can be designed with two or three heat zones.  Just specify the lengths and wattages of the zones you need.

Distributed Wattage Heaters

These heaters generally provide more heat at the ends and less in the middle, to maintain a consistent temperature along the length of the heater.  This is done by design of the heating element rather than by individual controls described above.
When specifying a distributed heater, specify the lengths and wattage percentages of each section.