機器
abandoned
abstract
aged
antique
background
big
brown
circle
closeup
cog
cogs
concept
construction
corrosion
decay
design
detail
dirty
engine
engineering
equipment
factory
force
gear
grunge
heavy
industrial
industry
iron
large
machinery
macro
mechanical
mechanism
metal
metallic
old
power
retro
rust
rusted
rusty
steel
technology
texture
transmission
vintage
weathered
wheel
work