Glossary Terms - H


The term used to designate the direction that a door swings in an opening. Term applies to both the door and frame. EGRESS and the secure side of the opening are considered when determining the hand.


A term which is used to indicate that the hardware or other component of the door opening must be used with the appropriate designated hand.

High Security Cylinder

A cylinder which provides extra resistance to picking and unauthorized duplication of keys.

Hinge Side

The side of a door that is in view when looking at the hinge knuckles on the door and frame. Also called the “Wide Side” because it is always slightly wider (on a beveled door) than the “Low Bevel” or “Stop Side”.

Hold Open

Maintains door at a particular degree of opening. A mechanical hold-open may not be used on labeled fire doors, which must be self-closing.

Hold-Back Feature

A hardware mechanism used to hold the latchbolt of a lock in the retracted position.


A hardware device used to hold a door leaf open at a required position. It may be either mechanical or in the case of a labeled door it must be electro-mechanical.

Hollow Metal

The term used to reference doors, panels, frame and partitions that are fabricated from cold formed steel sheet and coil. These doors and frames are internally reinforced and insulated, but are in a sense “hollow”, thereby the term HOLLOW METAL. The minimum gage of steel considered to be classified as Hollow Metal Door is 20 Ga. The C.S.I. Broadscope location for this product is usually found in Section #08110.


The part of a lock through which the spindle passes. When the spindle is rotated the hubs (if unlocked), actuate the locking mechanism.