`Detroit automotive steering components cold forming` (matches existing canon)

Used as scale comparison for cold heading — 10-lb truck steering knuckles done by warm forming, 1–2 lb car parts by cold heading.

They don't just make little parts like that. I've been through a plant in Detroit where they make most of the steering components for the car. If you look down where the wheel is and you see the steering knuckles — they can weigh 10 pounds on a truck, but on a car they might weigh a pound or two — they're made by cold forming. The ones on a truck at 10 pounds might be done by warm forming, all this deformation and forging at 500 or 600 degrees Fahrenheit, not 1,000 degrees. Usually they can do it at 500 degrees. It's called cold heading because it's the same process that people used for centuries to put heads on nails. But we can now make more complex things than heads on nails, and we can make them very fast. The tooling is kind of pricey, but it's very efficient. You can get very precise tolerances. But you better know how to make your dies. You're going to use the steel initially in a soft condition, but by the time it's finished it's gone way out on that stress-strain curve. You might have annealed it so it's soft; by the time you finished hopefully you haven't gone out to get fracture. You've done multiple operations to get more and more stretch. One operation might bring you to here, the next operation you're on a new stress-strain curve that takes you out to here, the next one a new stress-strain curve out to here, and you do this five or six times, and your total strain is a couple hundred percent rather than the limitation of 30 or 40% that you have in a simple uniaxial test. So that's the principle of multiple forming operations, and it applies to sheet metal too.