铁杵磨针，汉语成语，拼音是tiě chǔ mó zhēn ，比喻只要有决心，肯下工夫，多么难的事情也能做成功。出自南宋祝穆的《方舆胜览》。
Tiechu grinding a needle is a Chinese idiom. The pinyin is tiě chǔ mó zhēn. As long as you have determination and work hard, you can succeed in difficult things. From “Fang Yu Sheng Lan” by Zhu Mu in the Southern Song Dynasty.