Like David Haynes, my ferrous swarf is put into cleaned food tins, (baked Beans etc), The swarf is pounded down with a length of inch and ahalf (or 38mm) bar – exact size is less important than the weight). When filled to very near the top, the original lid is fitted and the the edges peened over , by working to and fro across diameters, to retain the swarf.
The tin(s) are then put into the Recycling Bin and go when the local council collect every fortnight.
Cuprous swarf, I (and other Society members) save in a plastic bag and take to our local Model Engineering Society, where one of the members takes our contributions to the scrap yard, when enough has been collected, to raise extra funds for the Club.
Old plastic knitting needles are a good starting point for some reclaims. (5L plastic containers of cutting lubricant are dispensed using reused soap dispenser pumps with a long needle drilled through to make a tube long enough to reach to the bottom. Also, by feeding from the bottom, it avoids the rubbish that always seems to appear on the surface of soluble oil solutions).
One day, I'll find a use for the metal ones!
In factories where I have worked, swarf has been mixed with concrete and then cast into long lasting floor tiles.
In my book, there is very little scrap metal, only when too small to hold, or already swarf.
"Not tight, just careful, y'ken"
Howard