hard as iron meaning in English

铁一样坚硬

As hard as iron
铁一样坚硬
The great timbers , darkened now by smoke , wormed in places , looking rotten on the surface , but hard in the core , hard as iron
这些大木材，表面上看被烟熏得黑黑的，有些地方被虫蛀了，烂了，但内芯却是十分坚硬的。
You re doing well , my friend , he said to the fellow with the bandaged head , and if ever any person had a close shave , it was you ; your head must be as hard as iron
“你的病情在好转，我的朋友。 ”他对头上缠着绷带的那个人说： “你可真是白捡了一条命，你的头简直像铁打的，怎么样？