3 sentences for 铁 (tiě — unshakeable)

1. 他是一个铁打的汉子。

   tā shì yī gè tiě dǎ de hàn​zi.

   He is a man of iron.

   Source: Dong Chinese Dictionary

2. 这是铁的事实。

   zhè shì tiě de shì​shí.

   This is an ironclad fact.

   Source: Dong Chinese Dictionary

3. 他放弃了铁饭碗，决定下海经商。

   tā fàng​qì le tiě fàn​wǎn, jué​dìng xià​hǎi jīng​shāng.

   He gave up his secure government job and decided to go into business.

   Source: Dong Chinese Dictionary