National Guard Products Inc.
1-800-647-7874
420N/520N
Automatic Door Bottom
WARNING: Do not pull drop bar out of case unless disengaged from spring or damage will
occur and void warranty.
Installation Instructions
1. For single doors cut 1/8" shorter than distance between stops on frame. For pairs cut 1/16" shorter than
distance between stop on frame and meeting edge of door. - DO NOT CUT UNTIL DROP BAR IS EX-
TENDED IN DOWN POSITION. Insert (2) nails provided into the small holes on the side of the drop bar to
keep drop bar extended while cutting. Do not cut from end with adjusting rod. MAXIMUM CUT door bottoms
36" and longer = 4", shorter than 36" should not be field cut, order net length.
2. With door closed, position on push side of door with adjusting rod toward hinge edge. Align bottom of case
flush with bottom of door and 1/16" clearance at each end, mark screw holes.
3. Drill pilot holes for screws using 11/64" drill bit.
4. Install with screws provided. DO NOT OVERTIGHTEN.
5. Set adjusting rod for proper seal. To reduce drop, turn adjusting rod right. To increase drop, turn adjusting rod
left. Once hinge end of drop bar makes solid contact, other end will drop. MAXIMUM drop = 7/8".
6. On wooden frames, install strike plate on door jamb where adjusting rod makes contact.
7. End cap with hexagon holes should be mounted to door at hinge side end to hold adjustment once set. Install
as illustrated below with screws provided. Blank end cap may be installed at other end on single doors only,
if desired.
2 5/16"
15/16"
7/8" Max Drop
POSITIVE PRESSURE TESTED GASKETING MATERIALS
FOR FIRE DOORS
FOR APPLICATION TO HOLLOW-METAL-TYPE FIRE DOORS
RATED UP TO 3 HOURS AND WOOD-TYPE FIRE DOORS
RATED UP TO 1-1/2 HOURS.
CATEGORY H
Smoke and Draft Control gasketing (Category H) tested to UL 1784; meets
requirements of NFPA 105, IBC for use on “S” label doors.
2.15
