The following terms define Building and Machine Parts
Lally column: steel pipe with concrete-filled post used to support girders.
landing: floor area at top or bottom of stairs.
lap joint: joint between two members in which end or edge of one is partly cut away to be overlapped by end or edge of the other, resulting in a flush surface.
latch: fastener, especially for door.
lath: narrow wood strips for lattice, trellis, and plastering base for wall; metal or gypsum panels nailed to studs on which plaster is applied.
lattice: wood strip framework.
leader: downspout connected to gutter.
leaf: sliding or hinged side or division, especially of door or window.
leaf spring: long, multiple spring used in suspension systems of vehicles.
ledger: wood strip nailed to underside of wood beam or stud for support.
lever: bar used to lift heavy object or pry open something.
ligature: thread, wire, or small hoop that serves for binding or tying up.
linchpin: fastener that prevents slippage; linkage device.
lining: inner coating or layer.
lintel: horizontal, weight-bearing crosspiece above door or window.
load-bearing wall: wall that carries vertical load from above.
lookout: extending horizontal framing member that supports roof overhang, fascia, and soffit.
lug and slot: projection and hole into which it fits.
lumber: milled hardwood or softwood boards, used to build construction and cabinetry.