Correct

铁石心肠

/ tiě shí xīn cháng /
Strokes
https://i.cchatty2.com/filters:format(webp)/fit-in/684x0/img/202102/铁石心肠-Chinese-idioms-Cchatty-0a893492-e574-420f-a967-5194a259974b-1612778340.jpg

Collocation

1
铁石心肠的人
2
真是铁石心肠
3
……(办某事)要有铁石心肠
4
为何如此铁石心肠

Definition

铁石心肠

Literally means:

be iron-hearted; have a hear to of stone

Actually means:

It means that one's heart is made of iron and stones.

Metaphorically it describes that someone has a firm character or an iron will and is unmoved by feelings.

心肠用铁和石做成的。

比喻性格或意志刚强坚定,不为感情所打动。

Example

Used as predicate, object or attributive. (作谓语、宾语、定语)
1
Lǎoshí
老实
shuō
  
,
guǒ
如果
tiěshíxīncháng
铁石心肠
  
,
jiù
huì
不会
zhèyàng
这样
yòu
bāngzhù
帮助
le
  

To be honest, if I had a heart, I wouldn't have helped him again and again.

2
Zhì
治理
huánjìng
环境
rǎn
污染
yào
yǒu
tiěshíxīncháng
铁石心肠
  
,
néng
xīnshǒuruǎn
心慈手软
  
,
gāi
de
yào
  
,
gāi
guān
关闭
de
gōngchǎng
工厂
dìng
一定
yào
guāndiào
关掉
  

To control environmental pollution to have a stone heart, can not be soft-hearted, the penalty to be punished, the closed factory must be shut down.

3
Biéren
别人
yǒu
kùnnan
困难
bāngzhù
帮助
  
,
biéren
别人
yǒu
wēixiǎn
危险
duǒkāi
躲开
  
,
zhèzhǒng
这种
tiěshíxīncháng
铁石心肠
de
rénxiàng
人像
nánhàn
男子汉
ma
  
?

Others have difficulties you do not help, others have danger you avoid, you such a hard-hearted person like a man?