How barbed wire is made

Before barbed wire, the first farmers around Fresno, California, spent nearly $4,000 on wooden fencing.

stations: 7
things upstream: 28
raw sources: 13
steps from the ground: 6

The short version

Steel billets are rolled into rods, then lubricated and pulled through dies into wire. The stiff wire is annealed so it bends, and galvanized against rust. In a barbing machine, two line wires feed in together and twist into a cable. A third wire enters from the side, wraps around the cable at set intervals and is cut at an angle, which leaves the sharp barbs.

Roll the rod

Ingots are heated and pushed through grooved rolls into billets, which are reheated and rolled down to wire rod.

Goes in
Steel
Draw the wire

Lubricated rod is pulled through dies, each narrower than the last. The wire comes out far thinner and very stiff.
Anneal it soft

Heating in molten salt, molten lead or a nitrogen furnace makes the stiff wire pliable enough to twist.
Galvanize the wire

The wire takes on a zinc coating to protect it from weather before going to the barbing machine.

Goes in
Zinc
Twist the line strands

Two wires feed into the machine together and twist into a single cable. Tension is set with care, as too little loosens the barbs and too much weakens the wire.
Wrap and cut barbs

A separate wire comes in from the side. The machine twists it around the cable and cuts it at an angle, forming sharp points at each interval.

Goes in
Steel wire
Reel it up

The finished strand winds onto a reel, ready to ship.

End of the lineBarbed wire

Worth repeating

Lucien B. Smith of Kent, Ohio, got the first U.S. barbed wire patent in 1867.
Joseph F. Glidden of DeKalb, Illinois, patented the modern design in 1874 after making his own.
Early farmers in Fresno, California, spent nearly $4,000 to haul in wood for fencing before barbed wire.