How toasters are made

Nichrome, the alloy in a toaster's glowing wires, survives being red hot again and again.

stations: 6
things upstream: 40
raw sources: 17
steps from the ground: 7

The short version

A press punches a sheet of aluminum and forces it into a die to form a hollow toaster-shaped shell. A machine wraps nichrome wire around sheets of mica, and two of them are bolted to the base on either side of the spring-loaded bread tray. A temperature sensor and a terminal board are fitted, and the shell goes over the base.

Punch the metal shell

A press cuts out a sheet of aluminum. A second press forces a punch into it inside a toaster-shaped die, and the metal flows backward around the punch into a hollow shell.

Goes in
Aluminum
Wind the heating wire

Nichrome wire, an alloy of nickel and chromium, is loaded into a machine that wraps it around a thin sheet of mica. Mica does not conduct electricity, and it keeps the wire in place.

Goes in
Nickel Chromium Mica Nichrome
Bolt in the elements

Two wrapped mica sheets are bolted to the toaster base, and a spring-loaded tray is set between them.
Fit the sensor and timer

A bimetallic strip is mounted on pivoting brackets with a spring and a release. Heat bends the strip until the release trips and cuts the power.
Wire the terminal board

Two sheet-metal conductors are layered around an insulating sheet to make a terminal board, which is screwed to the rack. The cord is threaded through the molded plastic base.

Goes in
Plastic Copper wire
Fit the shell and test

The shell is fitted over the base. Toasters are tested on the line for browning, shut-off temperature and total toasting time.

End of the lineToaster

Worth repeating

Albert Marsh created nichrome, an alloy of nickel and chromium, in 1905, and it solved the heating element problem that had held electric toasters back.
The earliest electric toasters had no temperature control, and the bread had to be turned by hand.
By the end of the 1940s, Sunbeam had a sensor that switched the heater off when the bread itself reached 310 degrees Fahrenheit.