Steeliness
/ˈstiːlinəs/
Definition 1 of 1
Pro Tip 1/3Emotional Strength
Use 'steeliness' to describe someone's strong emotional fortitude in tough situations. 
Her steeliness was apparent as she remained calm during the crisis.
Pro Tip 2/3Admiration Tone
'Steeliness' often implies respect for someone's unyielding character, especially in adversity. 
The team admired his steeliness in the face of defeat.
Pro Tip 3/3Not Rigidity
'Steeliness' suggests strength, not stubbornness or inflexibility. 
Despite negotiations, she maintained a steeliness that commanded attention, not anger.