Answer:
Deep, deep, do they go. Spreading out as they go. Never needing any air. They are sometimes as fine as hair.
My first is second in line; I send shivers up your spine; not quite shining bright I glitter in the light.
I may be made of metal bone or wood and have many teeth. My bite hurts no one and the ladies love me.
Ten men's strength, ten men's length. Ten men can't break me, yet a young boy walks off with me. What am I?
I like to twirl my body but keep my head up high. After I go in, everything becomes tight. What am I?
I am your mother's brother's only brother in law. Who am I?