metal rod;  metal bar;  iron rod;  iron club;  iron staff with rings on top (traditionally used by night watchmen)
 metal ring;  metal hoop;  trivet;  train wheel;  train
 iron mask (worn by samurai)
 hammer;  hopeless swimmer;  complete beginner at swimming;  someone who sinks like a stone
(arch.)  metallic;  cutting edge of a bladed instrument
 metal fork (used to poke a fire)