alloy
background
blank
bolt
brass
bronze
closeup
construct
construction
copper
damaged
design
dirty
element
frame
gear
gray
grunge
hardware
head
heavy
hole
industry
iron
mechanic
metal
metallic
old
part
pinion
plate
retro
rivet
rough
rust
rusty
scratch
scratched
screw
sheet
shiny
steampunk
steel
texture
tool
vintage
weathered
work
workshop
worn