Electric Cast-In Heaters

As a leading cast-in heater manufacturer for the plastic processing industry, Durex Industries has thousands of standard designs available for immediate use. Our cast-in products are based on years of expertise, developing these cast-in heater products for a vast array of equipment manufacturers.

Our electric cast-in heaters are made of aluminum, bronze, or other alloys for various heating applications. Used in a variety of industries including semiconductor and plastics processing, packaging machinery, food service, paper processing, adhesives, medical equipment, heat transfer presses, and textile manufacturing. Cast-in heaters can be used in any industry where highly efficient, precise heating is necessary.

Our design and production capabilities range from high volume cast platen heaters to complex, high precision, heated machine parts with unmatched temperature uniformity.  We accomplish through high vertical integration of virtually all design and production processes.

Advantages of Using Cast-In Heaters


Cast-in heaters are a desirable choice due to their durability. These robust heaters can withstand almost any environment. Additionally, cast-in heaters have the following benefits:

Custom Electric Cast-In Heaters

Durex Industries manufactures custom electric cast-in heaters, a unique heat source that can be adapted to many high-performance applications. Cast heaters are basically a heated part or tool that can be conceptualized and integrated as a component in a variety of equipment such as hot melt adhesive systems, food service, medical, packaging, paint spraying, semiconductor, and process pipelines.

The heating element is cast into aluminum, bronze, iron, or other metals and is an integral part of the final metal part. This allows for operating at a maximum heater efficiency and eliminates the need to supply a heater as a second component attached to a machined component. It is designed to eliminate the need for multiple part sourcing and assembly as well as provide a more uniform thermal process to your application.

Whether you have a basic concept or a complete drawing with specifications, Durex engineering can assist with the process of specifying cast-in heated parts to fit your application. Additional components such as terminal boxes, threaded fittings, special tubing, or temperature sensors can be cast-in as system requirements dictate.

Electric Cast-In Heaters for Plastic Processing


Our heaters are utilized as the standard for thermal processing on plastics process equipment throughout the world. Engineering of our electric cast-in products for extrusion applications is based on our years of expertise in the development of these products for the largest equipment manufacturers.

Durex has thousands of standard tooling designs available for immediate use or can custom design a cast heater to fit your application. Our in-house tooling capability can rapidly produce any design available on the market.

Cast In heaters for all plastics processing applications

Cast-In Platen Heaters


Durex designs and manufactures custom electric cast-in platen heaters. Platen heaters are a versatile cast-in design that can be adapted to a myriad of applications. Typical uses are heat transfer presses, foodservice equipment, die heaters, packaging equipment, and commercial pre-heaters.

Manufactured from aluminum or bronze alloys, the platen heater consists of a tubular heating element that is designed and formed to provide maximum efficiency and temperature uniformity on the working surface of the casting. The cast platens heaters can also be designed with integral cooling tubes or as stand-alone cooling platens for chilling applications.

Cast-In Ring Heaters

----2-Ring-Heaters.jpgCast Ring Heaters

Cast-in ring heaters are used in various punching, forming, sealing, and warming applications. They are also a direct replacement for mica style ring heaters. The cast in heating element delivers a robust construction in a low-profile design that is well suited for continuous production applications. The ring design can include mounting features such as cast mounting tabs, threaded inserts, and drilled holes. Ring heaters can also be designed as die sets for heated stamping applications.

Design your Custom Cast-In Heater Today

As an ISO9001 certified company, Durex Industries has the experience and capabilities to manufacture thermal solutions for almost any application. Our precision machining allows us to machine complex geometry and tight tolerances for custom cast-in heating applications. We are a vertically integrated company, meaning we manufacture all our heating elements as well as many of the custom components in our heaters. Our quality control and manufacturing processes are best in class, ideal for your next custom cast-in heater.

Heater Specifications & Options

Cast Materials Maximum Operating Temperatures
Aluminum 443 800°F (427°C)
Aluminum 319/356 700°F (371°C)
Bronze / Copper Alloys 1400°F (769°C)
Iron 900°F (482°C)

If required, other cast materials are available.

Cast Processes - Durocast™ perm-mold system uses steel permanent molds. No bake sand system for special castings and short production runs.

Machine Finish - CNC machining is performed for tight tolerances and complex configurations. Milled finishes are provided per specification. Belt sanding, lapping and polishing available to meet application specifications.

Standard Machine Finish Range: 64 to 125 rms.

Fine Finish Per Specifications: 8 to 32 rms.

Standard Flatness: Belt sanded, .015, Milled .005, Lapped, .001

Holes, Cutouts, Thermowells - Mounting or clearance holes, cutouts and thermowells, for inserting temperature measurement probes, cast-in or machined per your specifications.

Inserts - Threaded studs, precision component parts, bushings and special design parts cast acccurately in place.

Electrical - Resistance tolerance NEMA standard +10% -%5

Element Diameter .200 .260 .315 .430 .475
Maximum Voltage 240 240 277 600 600

Three phase available on large heaters. Maximum watt densities depends on size and application. Consult a Durex Engineer.

UL Component Recognition - DA Series cast in heaters are recognized per file E110394.


  • Electrical per UL 499 and UL 1030
  • Canadian Standard C22.2 No.72
  • Dimensional per specifications using Coordinate Measure Machine
  • Quality standard per MIL-Q_9858A


Electrical Data



  • The energy put out by a heating unit is measured in watts.
  • The power factor is always unity.





Cooling Tube Terminationsview images

Type C1 Termination - Plain cooling tube cut to standard 3" length extending from the heater. Specify longer length if required.

Type C2 Termination - 37° Flare nut fitting allows for cooling tube connection to a compression fitting.

Type C3 Termination - Compression fitting mounted directly to cooling tube provides seal for high pressure hook up. Available in standard 3/8 " and 1/2 " NPT. 3/8 " Dia. #55-0010 1/2 " Dia. #55-0011.

Type C4 Termination - Brazed seal with locknut provides an effective seal for high-pressure applications. Mating fittings available upon request.

Type C5 Termination - Brazed angle fitting mounted directly to the cooling tube with right angle 3/8 " FPT as standard. Specify L dimensions.

Type C6 Termination - Cast-in fitting with standard 5/8 " FPT for quick installation of cooling lines with no additional fittings.

Electrical Terminationsview images

Type S Termination - 10-32 threaded screw terminal with a ceramic insulator. Included nuts and washers. Type S standard for cast-in heaters. 6-32, 8-32 and metric sizes also available.

Type A Termination - Right angle terminal block seated on mica washers with 10-32 threaded stud. Included nuts and washers.

Type R Termination - Screw lug terminal seated on mica washers and welded to pin. Includes 8-32 screw for wire connection.

Type D Termination - Quick-disconnect spade lug with 1/4 " blade welded to pin. Other blade sizes available upon request.

Type T Termination - Ceramic insulator with a ceramic top for insulation of electrical connections. Includes complete Type "S" termination with 10-32 threaded stud.

Type HS Termination - Soldered directly to the heating element for moisture-proof termination. 10-32 screw terminal includes nuts and washers. Diameter: .430" - Length: 1 1/8" - Thread: 1/4 - 28, Diameter: .315" - Length: 1 3/8" - Thread: 10 - 32, Diameter: .250" - Length: 1 5/8" - Thread: 8 – 32

Type P Termination - Plain pin for field attachment of termination. Pin length is 1/2 " standard.

Type L Termination - Terminal lug with 10-32 screw is welded directly to the heater pin. Can be oriented straight or at a right angle.

Type C Termination - Flexible armor cable for abrasion resistance with a high temperature lead wire attached to the heating element. Specify L dimension when ordering.


Cast Heater Protective Housingview images

Type B1 Housing - Explosion proof cast iron housing with 1/2 " NPT double hub. Single phase design shown. Larger housing for 3 phase design also available.

Type B2 Housing - Explosion proof cast iron housing with 1/2 " NPT single hub. Single phase design shown. Larger housing for 3 phase design also available.

Type B3 Housing - Standard size stainless steel sheet metal box with two 1/2 " electrical knockouts. Other sizes and types available.

Type B4 Housing - Stainless steel terminal enclosure with male ERGE plug mounted on top. Mating connections available upon request.

Type B5 Housing - Die cast aluminum enclosure with 1/2 " or 3/4 " threaded electrical connections mounted to vented cooling tower. Other sizes and types available for single and 3 phase designs.

Type B6 Housing - Explosion resistant box with 1/2 " NPT single hub, designed for low profile applications. Single phase only. Different hub configurations are available.

Cast In Heater Special Services

  • Radiograph (X-ray): Confirmation of internal element configuration and casting soundness available through x-ray.
  • Plating/Coating: Electroless nickel plating, anodize, teflon® coatings and special blasted surfaces are available per customer specifications.
  • Pressure Testing: High pressure leakage testing is done in-house per application requirements.
  • Heat Treating: Stress relieving and aging through heat treating available as required.
  • CMM Inspection: Coordinate Measuring Machine used for precision quality control of tight tolerance machining requirements.
  • Helium Leak: Detect microleakage from casting body.
  • Temperature Uniformity: Conform heat uniformity across the finished surface.
  • Class 1000 Clean Room: Clean room assembly and packaging per class 1000 standards.
  • Solidworks 3D Modeling: Engineering software provides 3D models of proposed or existing product designs.
  • Custom Packaging: Customer specific packaging for delicate surfaces, large multi-product shipments, or long term storage.
  • Life Cycle Testing: Life cycle test chamber for longterm testing of uniformity and performance characteristics.
  • Material Certification: Precise records and certifications on materials which require traceability to specific standards.
  • Sensor Calibration: NIST traceable calibration lab for calibration and certification of any temperature sensor requirements.
  • FEA Analysis: Preview of proposed design constructions using FEA analysis.

Installation & Maintenance Guidelines for Cast Heaters

  • Always ensure that cast-in heaters are properly mounted to the application to avoid warping of flat heaters or "walking" of barrel heaters. After the initial start-up, retighten the heater mounting system to assure complete surface contact. Periodically check the bolts or straps and tighten as required maintenance.
  • Tighten all liquid cool connections securely to avoid rupture from internal steam pressures. Cast in C6 fittings or brazed connections are the most reliable. Properly maintain these connections to avoid leaks that will destroy the heater. Do not operate heating and cooling simultaneously to avoid thermal shock of the cooling tubes.
  • It is recommended that water used for liquid cooling applications be treated to avoid corrosion and hard water deposits that will clog the cooling tubes over time.
  • Install proper temperature control prior to operation of the heaters to ensure protection from over-temp situations which may damage the heater or equipment. Periodically changing temperature sensors is good preventive maintenance.
  • Electrical terminals must be properly insulated and made tightly to ensure safe operation. All heater installations must be properly grounded. All electrical terminations must be made per applicable Electrical Safety Codes and O.S.H.A. regulations.
  • Do not operate the heaters outside of the voltage and temperature of the design. This will cause the heaters to fail.
  • ALWAYS disconnect the electrical power to heaters prior to service.

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