Post-WWII cold heading machine phosphate-stearate surface treatment

Extended description of cold heading — the post-WWII innovation of phosphate + stearate surface treatment that enabled cold deformation of steel wire into precision fasteners at seven parts per second. Used as the competitive baseline that pixel-by-pixel additive cannot match for commodity fasteners.

There's another process. Back when I was a young assistant professor, I went to Pittsburgh once and I don't remember why, but I went through a plant doing cold heading. Cold heading was developed after World War Two when someone learned that if I put a phosphate coating on steel — how do you put a phosphate coating on steel? You just dunk it in phosphoric acid. Is that hazardous? It's Coca-Cola, right? Coca-Cola is just phosphoric acid. So it's not all that hazardous. The other day a classmate of mine was here who used to go through a case of Coca-Cola a day, and he ended up in the infirmary with anemia, because he lived on Coca-Cola and M&Ms. Couldn't figure out why he had anemia. But if you phosphate-coat this — you take a wire, this is 3/8 inch diameter wire, phosphate coated, then put it in a stearate bath. Stearate — what's that? It's soap, same type of thing. Stearic acid, it's a stearate.

Tom's standing demo of a zinc-plated furniture-fastening insert. Pre-WWII these parts cost ~$1.50 (automatic screw machine); post-WWII phosphate-and-stearate surface treatment enabled cold heading them at ~$0.05. The porous iron phosphate surface anchors a calcium stearate "grass" lubricant (polyethylene-chain rooted by polar bond), enabling repeated deformation steps without die galling. Decibel anecdote (125 dB, 130 dB threshold of pain) from his plant visit.

Other things about adhesives. I showed you aluminum oxide and how we roughen up the surface by anodizing aluminum. Just after World War II, someone discovered that you could phosphate steel. [Tom holds up a small fastener.] This is a zinc-plated mechanical fastening piece that allows you, if you're making particle board furniture, cheap stuff, to embed this in the surface: drill a hole, embed this — it's got little knurled edges — and then put a screw through it. It comes in the bottom, it's got a shoulder, and you can put a regular old machine screw through this. It's threaded on the inside, and you can make a strong joint to a piece of particle-board junk furniture.