The shelves are pieces of metal with many small holes through them.

VOA: special.2009.11.30

Due to an explosion, a metal pipe went through his head like so.

由于一场爆炸,一根钢管刺穿了他的脑袋,就像这样

耶鲁公开课 - 心理学导论课程节选

The artist uses a fine sharp knife to cut through the metal.

VOA: special.2009.09.02