Historical
UL 63 Ed. 4-2003
Outline of Investigation for Fire Door Frames - Published Date: May 20, 2003
1.1 These requirements apply to frame assemblies for swinging fire doors, which have demonstrated in fire tests fire-resistive properties sufficient to warrant their use with fire doors having a rating of 3, 1-1/2, 1, 3/4 hour, or 20 minutes when tested in accordance with the Standard for Fire Tests of Door Assemblies, UL 10B, or the Standard for Positive Pressure Fire Tests of Door Assemblies, UL 10C. The frames may include provision for transoms, mullions, or sidelights.
Underwriters Laboratories [ul]