• Drum: To be formed with 26-gauge galvanized steel sheet rolled around and attached to stamped 16-gauge galvanized steel drums to restrict deflection to .03” per foot (2.5 mm/m) of door width.
• Springs: To be oil tempered, grease packed helical torsion type designed to cycle 12,500 times with an overload factor of 25%. Springs are to be mounted on a 1-5/16” (25.4 mm) hor rolled steel tubing of minimum 14-gauge.

Support Brackets: To be 3/16” (4.76mm) thick structural steel angles and ¼” (6.35 mm) thick steel diagonal brace welded in a triangular form to support ends of drum assembly.

• Rope Pull: To be 1/4″ (6.35mm) polyester rope attached to bottom angle up to 10′ x 10′ (3048mm x 3048mm) doors.
• Chain Hoist: To be cast iron pocket wheel drive with machine link hand chain for over 10′ X 10′ (3048 mm x 3048 mm) doors.

• Guides: To be roll formed 16-gauge galvanized steel channels.
• Guide Depth: 2-1/2” deep per side to provide sheet penetration adequate for proper operation.

• Side Draft Seal: Brush seal with aluminum retainer (field installed).
• Top Draft Stop: to be E.P.D.M. seal attached to top of curtain to seal against header (field installed).

• Hand Chain Lock: bracket, to be mounted on guide angle or wall for chain operated doors.
• Curtain Lock: to be hardened galvanized steel slide bolts attached to bottom angle suitable for padlocking. (padlock by others)