Screw plug immersion heaters are ideal for heating liquids in process tanks and vessels. Available in a number of sizes, materials, and designs, screw plug heaters are used in a wide variety of applications and industries including caustic solutions, fuel oils, clean water, heat transfer oils, liquid paraffin, and many others. Browse the customizable features and capabilities of our screw plug immersion heaters.


Screw Plug Immersion Heater Features

We manufacture screw plug heaters to fit your requirements, including different sizes, materials, and wattage.

Easy Installation

Our screw plug immersion heater fittings can be screwed into the threaded opening of a tank, vessel, pipe, or machine component.


Each custom-made screw plug heater is available in a variety of sizes and material combinations to meet your application needs.

Compact Design

Convenient for use in tight spaces, we can design and build screw plug immersion heaters for small tanks and vessels.

We Can Make a Custom Screw Plug Heater for You

Do you need screw plug heaters in a non-standard shape? Need to replace a British or Japanese thread? Or a replacement for a discontinued screw plug immersion heater? With 70 years of experience in the industry, there isn’t much Heatmax has not built before. Send us a picture, sketch, or sample of the screw plug heater you require, and we can engineer it for you.


Screw plug immersion heater voltage can be supplied up to 600V.


Each screw plug heater element is built to conform to the space available.

Screw Plug Fittings

Standard North American NPT fittings available in 1”, 1¼”, 1½”, 2” 2½”, and 3” sizes for our screw plug immersion heaters while Standard British Parallel Pipe fittings available in 1½” and 2” sizes.

Screw Plug Material

Screw plug immersion heater materials are available in various alloys including Steel, Stainless Steel, Titanium, and other specialty alloys.

Element Sheath Material

Screw plug heater element sheath materials include Copper, Stainless Steel, Titanium, and Incoloy. Specialty alloys include Hastelloy, Incoloy 600, Monel, and Alloy 20.

Wattage and Watt Densities

Our custom-made screw plug heaters can be designed with any requested wattage or watt density rating – within engineering limitations.

Element Numbers

Element numbers are available in configurations of 1, 2, 3, or 6 for increased heat output. Element spacers are available for our screw plug immersion heaters.

Terminal Boxes

A screw plug heater with a NEMA 1, NEMA 4, NEMA 4/7/9 box is available to meet the demands of your application.

Thermostat, Thermocouples and Thermowells

A screw plug immersion heater with a thermostat may be added to any heater per your specifications.

Electro-polish and Passivation

Electro-Polishing and passivation can be applied to the steel sheath of the screw plug heater element. These processes remove surface imperfections and contaminants to protect test materials from contamination, especially in medical and food applications.

Technical Drawings for Screw Plug Immersion Heaters

Talk to Us About a Custom Screw Plug Immersion Heater

Speak with a Heatmax sales engineer about your project and our in-house team will manufacture a screw plug immersion heater customized to your specifications. We’ve been in business for almost 70 years and built all kinds of unique screw plug heaters. Whether you require screw plug immersion heaters for small tanks or applications that necessitate specific voltages, element materials, thermostats, and much more, Heatmax will work with you through every step of the process.

Ask A Screw Plug Heater Expert


Almost 70 Years

Heatmax History

Founded by an ex-Navy engineer, George Strokes, the company got its start making quartz immersion heaters in Euclid, Ohio in 1952.

George called the company Glo-Quartz®.

Growing rapidly he moved the company to bigger premises in Willoughby and then Mentor. Other factories were opened in Pasadena, California (now closed) and then Tucson, Arizona.

Tom Strokes took over leadership of Glo-Quartz in the mid-70s and moved to roll reduced metal heating element range.

A final legacy, Tom launched a new brand name, Heatmax Heaters, in 2020. The new brand name both better represented the wide range of products we make and challenged the common perception that we were quartz heater specialists only.