HARD AS NAILS

{adj. phr.}, {informal} 1. Not flabby or soft; physically very fit; tough and strong. * /After a summer of work in the country, Jack was as hard as nails, without a pound of extra weight./ 2. Not gentle or mild; rough; stern. * /Johnny works for a boss who is as hard as nails and scolds Johnny roughly whenever he does something wrong./