Mechanical parts Human hands Human skin Tools of trade Craftsmanship on display Hands at work Hand protection Manual labor Dirty hands Hand washing Hands in harmony Brown dirt Covered hands Mechanical work Tireless effort Hard labor Dirt on fingers Stained skin Manual work Hands at end Grime on fingers Skilled labor Filth on human skin Marks of hard labor Industrial grime Grime on palms Oil fluid Cleanliness challenges Challenges of job Mechanical filth