abstract
aluminum
background
black
broken
business
cargo
dirty
dump
ecology
economy
environment
factory
friendly
garbage
heap
heavy
industrial
industry
iron
junk
junkyard
loading
material
metal
metalwork
old
outdoors
parts
pile
production
protection
recycle
recycling
resource
rubbish
rust
scrap
sharp
stack
steel
technology
texture
trades
transportation
trash
tube
used
waste
yard