Residential door hinges half surface steel. Boxed - pair 3-1/2 inches by 3-1/2 inches. Pack of 2 includes screws. Five knuckle for use on interior doors up to 70 pounds Non-rising, removable, flush steel pin aids with installation or door removal. Ideal where doors do not have trim to clear. Easy to apply as only the frame leaf is mortised, no gauging necessary. Made of steel, toughened and hardened by cold rolling. made of steel toughened and hardened by cold rolling.