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DF Series Tornado-Rated Frames

The DF Series 3-sided flush frames are assembly tested and approved showing tornado resistance to extreme effects of 250 mph winds for impact and wind load pressure, labeled by Intertek signifying compliance to ICC 500-2014 and FEMA 320/361.

DF Series frames are installed as part of the wall framing sequence and can be specified as KD (knock-down) for field assembly prior to installation or SUA (set-up and welded) for installation as a pre-welded unit.


Strength, durability and ease of installation

  • 14 gauge A60 galvannealed steel for superior corrosion resistance on exterior openings
  • Die-mitered corner connections at the head and jamb. Standard corners ensure attractive, tight and closed miters
  • Patented universal hinge preparations allow for easy field conversion from standard weight .134" (3.3 mm) thick hinges to heavy weight .180" (4.7 mm) hinges
  • Adjustable base anchors allow for installation adjustment when the floor is not level

Approvals and specified industry standards

Listed and labeled by Intertek showing compliance with ICC 500-2014 and FEMA 320/361. Republic DF Series ICC500 Tornado Assembly Listing with Intertek.

Exceeds industry standards

  • Republic is SDI Certified through regular audits to ensure manufacturing, performance and quality standards set by the Steel Door Institute
  • Overall frame construction exceeds ANSI A250.8-2017 (SDI-100), the standard set by SDI specifying sizes, design, materials, construction, finishing and performance for standard commercial steel doors and frames
  • Tested and Intertek labeled showing compliance with ICC 500-2014 and FEMA 320/361
  • Hardware preparations and reinforcements meet ANSI A250.6-2003, and locations meet ANSI/DHI A115, unless otherwise stated
  • Frames meet fire rating requirements; they are listed for installations requiring compliance to both neutral pressure testing (ASTM E152 and UL-10B) and positive pressure standards (UL-10C)
  • Factory-applied baked-on rust inhibiting primer meets ANSI A250.10-2011

Typical applications

Commercial buildings in tornado alley as well as residential shelters, commonly new school gymnasiums constructed as ICC 500 compliant tornado shelters for K-12 and higher education.

Frame anchors are approved to lock the frame to the shelter walls built as new or existing CMU block walls, poured concrete, or steel.

Technical Data Guide

For more information, download the Republic Technical Data Manual.

  • DF Series (Pages 48-63) includes Construction, Installation, Anchors, and Hardware preps, Glass lights and handing, Shutters and handing, Gasketing and thresholds, and Approved hardware