Pellets of acetal resin, sold as Delrin, are melted and injected into steel molds to form the body and base. Acetal shrugs off fuel and survives being dropped, which matters for a tank that holds pressurized gas in a pocket.

Serrated, hardened steel wire becomes the spark wheel. Thin steel is formed into the hood that covers the wheel and the guard that shields the flame.

An aluminum valve, a brass jet and small springs of low-alloy steel drop into the body. The valve opens only while the thumb lever is held down, and the jet meters gas to the flame.

An ultrasonic welder buzzes the plastic body and base together until their surfaces melt into one sealed reservoir. No glue is used.

Automated machines push liquefied isobutane into the reservoir and then seal the fill hole with a small ball. The gas stays liquid under its own pressure until the valve lets some out.

A spring presses a short rod of ferrocerium up against the spark wheel, and the steel hood snaps over both. Rolling the wheel tears hot particles off the rod, and cerium ignites at only 150 to 180 °C.

Each unit is struck to check that it lights, that the flame holds a steady height, and that the tank does not leak. Safety standards also require a deliberate push to light it, such as a lever force of at least 15 newtons.

Logos and designs are printed onto the body before the finished units go into trays, boxes or blister packs.