Glossary - N

narrow stile lock (np)
mortice lock with a case depth of less that 67mm

necked bolt (np)
bolt ² with cranked end to shoot ²

Nettlefolds bolt (np)
bolt ¹ comprising two contra-acting claws which withdraw into a fixed head projecting from the forend

Nettlefolds lock (np)
lock with a Nettlefolds bolt

nib head screw (np)
screw with the driving feature (hexagon, circle with flats etc) separated from the screw head by a narrow neck which is designed to twist and break at a pre-determined torque

nib ward (np)
ward made by pressing inward a portion of the cap or case

night latch (np)
lock with automatic bolt which is withdrawn from outside by key, and from inside by handle or knob

night vent (np)
fanlight which opens

non-handed (adj)
suitable for closing in either direction (clockwise closing or anti-clockwise closing)

nosing (of a key bit) (n)
curvature on the corner of a key step to remove sharpness and reduce the wear on the lever

nozzle (n)
circular boss containing a keyhole