Question About "Cal Rod" Origin

CALorie, meaning heat?

Inside a Calrod tube are ni-chrome wires surrounded by a filler material. . Calrod is a trademark for a type of heating element made by General Electric. My guess is the name comes from the function. Calorie = heat measure Rod = tubular form, thus Calrod = commercially made tubular heating element. They are far more rugged than stretching a ni-chrome wire in the oven.

So, my guess would be: a ni-chrome wire, surrounded by ceramic (of some sort), surrounded by a steel tube. So Calrod is like "Scotch Tape" or "Frigidaire" (if you're old enough).

Google tells me "Magnesium Oxide" is the insulation inside the tube.

"Asperin", "Xerox",... Yes.

Cal rods are indeed VERY durable. I fix machines that use them heated to 300 degrees every day for 20 years and up. The american made ones never fail, chinese??? well not so great.

The only reason I replace them is customers breaking or more notably cutting:( the wires off the end...

CAL RODS are basic life of product devices.