Nail: a pin-shaped, sharp object of hard metal or alloy steel, used as a strong fastener. Nails for specialized purposes may often be dipped or coated to prevent corrosion in harsh conditions like weather or chemically treated wood. Nails hold materials together with friction in the axial direction and shear strength in lateral directions. The point of the nail is also sometimes bent over or clinched to prevent it from pulling out.
Nail Head: flat, enlarged top part of the nail that is struck by the hammer.
Nail Punch: hand tool consisting of a metal rod with a tapered head, used for setting nail heads below the surface of wood.
Net Floor Area: gross floor area, minus the area taken up by partitions, stairs, columns and various floor openings.
Newel: the upright post about which the steps of a circular staircase wind. Also the main post at the start of any stairs, also the stiffening post at a stair landing.
Niche - recessed space in a wall used for placing various decorations.
Node: in a truss, the meeting place of two or more members.
Nominal Size: in lumber, the standard commercial dimension by which it is known and sold, as opposed to the exact dimensions. Nominal means "in name only".
Nonbearing Partition: partition that reaches from the floor to ceiling which does not support any load excpet it's own weight.
Nosing: stair tread portion extending out over the vertical riser. Also can refer to the rounded portion of a board.
Notch: V-shaped depression in a piece of wood used in joining large wood members, for example in log cabin construction.