Steel or aluminized steel sheet is punched, perforated and drawn into the basket, the drip pan and the inner cooking chamber. The holes let hot air pass under and around the food.

Parts that touch food are sprayed with a PTFE nonstick coating, or a ceramic one on some models, then baked so the coating fuses to the metal.

A nichrome coil is centered in a stainless steel tube packed with magnesium oxide powder, and the tube is drawn through a die to compress that powder. The sealed rod is then bent into a flat spiral.

An electric motor with a metal fan blade is fixed in the lid above the element. The fan pushes air past the hot element and down onto the food at high speed, thinning the layer of cool air that clings to its surface.

Heat-resistant plastic is injection molded into the outer shell, the drawer front and the handle. An air gap and inner metal walls keep the outside cool enough to touch.

A control board with a timer, a thermostat sensor and a display is wired to the element and the motor, along with a thermal fuse and a switch that cuts power when the drawer is pulled out.

The chamber, lid and housing are screwed together and the drawer is fitted. Each unit is run hot on the line to check temperature, fan and cutoffs before packing.