be as hard as nails

to have no feelings or sympathy for other people She'll be good in business - she's as hard as nails.

Name	Pronounced	Usage
Aitor	-	Basque
Gerfried	GER-freet	German
MÁIrÍN	MOI-reen, MAW-reen	Irish
Tea	TE-ah (Finnish)	Croatian, Slovene, Swedish, Danish, Norwegian, Finnish
Sheryl	SHER-əl	English
Tiia	TEE:-ah	Finnish