Hand Nails, particularly un-galvanised ones are very hard to sell in the Western world. This is due to cheapness and removability of screws, most people having a cordless drill now, and professionals having a nail gun.
Another use is needed for these millions of nails, these ideas may help.
Perhaps using the methods and machinery of plastic recycling as illustrated in www.preciousplastic.com to extrude plastic, a nail or length of rebar can be covered to make a peg.
This can then be cut to length for insertion into a pre drilled hole when building or strengthening a shelter in the third world, .
These will be thicker than normal fixing with a compressible plastic outer skin .
This may have an advantage in creating a more flexible, stronger joint in an earthquake or storm, allowing the shelter to survive a stronger force.
Alternatively, wall plugs may be made like these 300mm Wall Plug, Cut To Length, Self Centring Screw Expanding Stick can be manufactured & cut to length .
Then Nails can be inserted & / or glued
buntublox.com or Rebar framed Eco-Brick shelter frames to make it stronger and more rust resistant
This idea by P Ridley of cabinz has been posted on the www.PreciousPlastics.com ideas forum
Coating Metal Nails & Rebar in Recycled Plastic https://davehakkens.nl/community/forums/topic/coating-metal-nails-rebar-in-recycled-plastic/