咬钉嚼铁

Explanation: Teeth to chew nails. Metaphor of a strong will. 　　Usage: Joint type; as the predicate attribute; with compliment 　　Source: Ming Dai "Dream Recollection four Qi Tao Xiang only addiction," only the Cheung fine temperament, bite chew iron nails, the word a hundred mill, mouth Qinshou, Bao generation Jieneng Triton idea. "