Specifications General: The series 6063T-5 aluminum widnow shall comply and bear the quality certification label in accordance with the ANSI/AAMA Certification Program. Material: Aluminum window frames and sash members shall be of 6063-T5 extruded aluminum alloy within commercial tolerances. Integral fins to have suitable break-off and nailing grooves. Finish: Windows to be finished in natural aluminum extruded mill finish. Bronze or white acrylic electrostatically applied enamel finish available if specified. Construction: All joints of frame and sash members shall be neatly fitted, securely connected and permanently watertight. Frames shall have step point construction for maximum rigidity. Both frames and sash members shall use an extruded screw boss that is an integral part of the extruded section. The operating sash shall interlock at both meeting rail and sill. The operating sash shall be easily removable from inside and not removable when in locked position. Mullions to be furnished as required. Weatherstripping: Weatherstripping shall be silicon treated, fungus, mildew, and moth resistant high performance poly bond fin seal around the complete perimeter of the operating sash with a permanent poly fin in the middle of the poly pile to minimize air infiltration. Vertical stiles are weatherstripped. The poly pile weather