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B Series Flush Doors

B Series stiffened core doors add internal steel stiffeners, extending the full width and height of the door. These doors are designed to meet the architectural requirements for full flush doors, from heavy to 14 gauge maximum duty. Premium standard door construction combines a beveled lock and hinge side, strong epoxy filled interlock edges, and unsurpassed 7 gauge hinge reinforcement. 

B Series doors have a higher than normal resistance to impact damage.





Strength, durability and ease of installation

  • Steel stiffened core construction using 20 gauge hat section stiffeners located 6" apart and welded 5" on center the height of each stiffener, filled with 1 pound fiberglass batting between stiffeners
  • Beveled hinge and lock side edges have tighter tolerances and smaller gaps between door and frame face for a better visual appearance and ensuring easier operation and eliminating binding and sticking
  • Full height, epoxy filled mechanical interlock edges provide structural support and stability the full height of the door edges
    • Edges may be filled (with tack welds around openings) or may be stitch welded and filled, which is proven to be more structurally sound than continuously welded edges (which are commonly weaker due to heat buildup)
  • Patented universal hinge preparations allow for easy field conversion from standard-weight to heavyweight hinges
  • Standard 14 gauge inverted top and bottom channels provide excellent door stability, and is able to be dressed with top and bottom caps
  • Recessed Dezigner Glass Trim creates clean edge, flush with the door surface

Exceeds industry standards

  • Steelcraft is SDI Certified through regular audits to ensure manufacturing, performance and quality standards set by the Steel Door Institute
  • Overall door 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
  • Hardware preparations and reinforcements meet ANSI A250.6-2003, and locations meet ANSI/DHI A115, unless otherwise stated
  • Doors meet the broadest 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

Environments that require additional resistance to localized impacts and vandalism, such as detention centers and behavioral correction facilities. While our normal honeycomb core provides the best structural integrity in testing, especially considering the weight of the door, a larger localized impact to the door face can be resisted better with a steel stiffened core.

For STC 40 / Sound doors, specify the STC-Stiffened core construction with back to back stiffeners and gap between to reduce sound transmission over typical STC 35 L Series honeycomb doors in third party lab testing.

Technical Data Guide

For more complete information on B Series doors, download the Steelcraft Technical Data Manual.

  • B Series (Pages 109-112): Includes options (p 125), lights (p 153), hardware preps (p 235), fire rated products (p 277), performance (p 323)