Sentences with Hard As Nails

The old fortress, hard as nails, withstood centuries of storms and battles.

The veteran boxer's jaw was as hard as nails, having endured countless blows throughout his career.

Despite the harsh winter, the ancient oak tree stood hard as nails, undeterred by the freezing winds.

The scientist marveled at the metal alloy, hard as nails, that could withstand extreme temperatures.

The negotiator remained hard as nails during the intense discussions, never revealing a hint of emotion.

The software's security system was hard as nails, impervious to hacking attempts.