"NN" wrote in message
oups.com...
I have someone trying to collect aluminum for recycling and he is
asking me if this is aluminum or not? If I tell him that whenever a
magnet does not stick to metal, it is aluminum? At least with a 95%
accuracy for junk around a farm?

Purt nigh. It won't be magnesium. OTOH if there's a 'nuclear' symbol on the
outside all bets are off.