A narrow strip of material placed between window sash or door panels and frame to keep out rain, air, etc. May take many different forms, depending on product design and usage. Welding 

 Invisible rays of the spectrum at its short-wavelength violet end; the invisible solar radiation that can cause heat buildup and fading of wood, fabrics and other surfaces. (Low-E coatings are added to window glazing to moderate or eliminate harmful undesired UV wavelengths of light.) United Inch 

 A term that describes the expansion a material exhibits when exposed to high temperature, or the shrinkage (contraction) that results when exposed to low temperatures. Threshold 

 Refers to a physical property that affects the extent to which heat or cold is transferred by a material. For example: aluminum has 1,000 times the thermal conductivity of Fibrex™ material

 An element (space or other material) placed between other elements to reduce conduction. (Andersen uses a vinyl thermal break on patio door

 See Inside Stop, Outside Stop, Parting Stop. Storm Door

 A seasonal second window installed on the outside or inside of a window to provide additional insulation or protection from bad weather and allow ventilation. Tempered Glass 

 A door fitted with two or more panels that move horizontally on a track or in grooves. Solar Heat Gain Coefficient (SHGC) 

 A glazed sash or panel that cannot be operated. Stile

 A thin slip of material for straightening jambs and leveling window and door frames. Shims are also used to adjust hardware positioning. Term is also used to describe the action of bringing to a level by inserting a shim. Side Jamb