abstract
architecture
background
bend
blur
bull
bundle
circle
coil
construction
factory
foundry
grey
hard
heavy
helix
hot
industrial
industry
inventory
iron
loop
manufacturing
material
metal
mill
motion
pattern
plant
pressure
process
product
production
rod
roll
round
shiny
silver
silvery
spiral
spool
stainless
steel
tie
tool
wire
zinc