All of the nouns used (hammer, chain, furnace, brain, anvil) are explaining mighty things that the tiger is being compared to. The poem is simply saying that they are smart, speedy, and strong.
I hope this helped! If you have further questions don't be afraid to ask!
~Travis
It maybe man mater of his destiny i gueesed
They don’t know whether or not the promises that were made will be kept.
I got a 100 on that question, and this is what I put
Discriminative , judging , cruel , insulting , horrible
