One of my dad's first jobs out of college was designing needle-grinding machines for BD. they have a relatively complex 3-facet cutting edge, but the plastic hub allows you to accurately orient them on the grinder. I can imagine collecting, cleaning, sterilizing, and resurfacing needles could be a cottage industry in the developing world. 23G 1.5" becomes 23G 1.25", and so on.

https://www.google.com/search?q=micrograph+of+hypodermic+nee...

https://www.ncbi.nlm.nih.gov/pubmed/2773053