Hinges support the weight of the door in use. Doors equipped with closers should have antifriction bearing hinges for smooth operation. Bolts are part of the door's locking capacity, though they are independent of the lock mechanism. The bolt protrudes from the lock and holds it to the strike. The cylinder contains the springs and tumblers that allow the keys to operate.
Exit devices are latches released by pressing some type of touch bar.
Closers control the door movement throughout its opening and closing swing. Accessories are items added to the door, such as weatherstripping. This new testing is done under realistic conditions - warm air builds up on the top, and cooler air stays in the bottom of the room. As a result, the top half of the door is pulled one way and the bottom half the other, with a neutral pressure plane in between. Doors must stay latched under these conditions.