How Slinkys are made

A Slinky wraps 62 feet of flattened steel wire around a spindle about 80 times, then pops out every 15 seconds.

stations: 5
things upstream: 26
raw sources: 12
steps from the ground: 6

The short version

A Slinky is one long ribbon of spring steel. Round wire comes in on huge spools, passes through a flattener, and winds around a spindle into a coil. Each end is crimped for safety, and the finished coils tumble off a conveyor into boxes. The flattener and coiler were designed by the toy's inventor.

Unspool the steel wire

Galvanized spring steel wire comes in on spools of 2,000 pounds each. Spring steel is chosen because once wound, it doesn't unwind.

Goes in
Steel wire
Flatten the wire

The round wire is fed through a flattener at 12 miles an hour. It leaves as a thin flat ribbon, which gives the coil its smooth edges.
Coil it on a spindle

A coiling unit wraps about 62 feet of ribbon around a spindle about 80 times, and spits out a finished Slinky every 15 seconds. The original from 1945 stood 2 and a half inches tall and had 98 coils.

62 feet of wire, about 80 turns
Crimp both ends

A band is crimped around each end of the coil so the sharp wire end cannot jab a child. This step began in 1973.
Drop into the box

Finished Slinkys travel single file along a conveyor. At the end of the belt each one does a somersault, its first step, and is pushed into a box that is sealed automatically.

End of the lineSlinky

Worth repeating

The Slinky was born in 1943 when a naval engineer watched a tension spring fall off a shelf and keep walking.
All 400 of the first Slinkys sold in 90 minutes at a Philadelphia department store in 1945.
Soldiers used metal Slinkys as portable radio antennas in the Vietnam War.