機器
aged
architecture
big
bolt
brown
chain
concept
construction
danger
dirty
element
equipment
factory
grunge
hardware
head
industry
iron
material
metal
metallic
old
orange
parts
pipe
pipeline
point
pressure
protection
red
rough
rust
rusty
safety
screw
service
shiny
solid
spare
steel
supply
surface
symbol
tool
vintage
water