Sally Hansen® Hard as Nails® Natural Tint Strength Treatment. The nail clinic in a Bottle!®. Helps prevent chipping, splitting cracking. 0.45 fl oz 13.3 ml. What it is. The original strengthening treatment, hard as nails gives nails a smooth, chip-resistant surface & helps to provide long-lasting protection. Nails grow longer & stronger. How it works. Nail edges are sealed for protection against chipping, cracking & splitting. The results. Longer, stronger, harder nails with a beautiful natural tint. Salon tested. 1-800-953-5080*. *USA/Canada only. sallyhansen.com. 24M.