New Millennium Building Systems

Castellated and Cellular Beams

New Millennium offers FreeSpan™ castellated beams and cellular beams for a highly architectural and cost-effective structural option. The typically longer spans erect faster. Lighter framing reduces column and footing sizes. Web openings allow mechanical, electrical and plumbing to pass through. FreeSpan™ castellated and cellular beams can be left exposed for an aesthetic look.


FreeSpan™ castellated and cellular beams

  • Spans up to 100 feet
  • Depths up to 66 inches
  • Straight, camber and combined weight options
  • Galvanized options are available
  • Easily fireproofed on jobsite by others
  • Made from 96% recycled materials
  • Longer span beams erect faster
  • MEPs pass through web openings
  • Architecturally appealing when exposed

FreeSpan™ castellated and cellular beams offer greater strength-to-weight ratio

Castellated and cellular beams are manufactured by cutting a hot rolled beam lengthwise, using computer controlled plasma arc torches, often in a half-circle or half hexagon pattern. The split halves are then offset and welded back together to form a deeper beam with full circular or hexagonal shaped web openings. The resulting beam is approximately 50% deeper and much stronger than the original hot rolled beam.


Appearance and performance of FreeSpan™ castellated and cellular beams

The depth of a simple, straight castellated or cellular beam can be highly customized as to appearance. The strength of a castellated beam can be precisely matched to the load. Castellated and cellular beams are readily available with either hexagonal or circular openings. An advantage of castellated beams and cellular beams is that they support long, clear spans often desired in office buildings, hospitals and parking garages.


Castellated and Cellular Beams Parking Garage

Lighter beams can be used to span greater lengths, up to 100 feet and are ideal for parking garages in conjunction with metal decking. Lighter sections can be used for the top portion of the castellated beam and a heavier section on the bottom to further increase the capacity and reduce the weight.


Cambered beams

Because the castellating process splits the beam into two flexible halves, it is easy to manufacture FreeSpan™ castellated and cellular beams with camber for floor applications. The beams can be assembled with the appropriate camber needed to offset the dead load deflection of the concrete slab.


Asymmetric beams for composite deck

Another FreeSpan™ beam design option is to combine a lighter upper half beam with a heavier lower half beam, which are cut from two separately produced beam sections. This works well for composite deck applications, as a subfloor steel beam supporting a concrete floor. The studs can be welded to the top flange of the castellated beam to solidly anchor the concrete to the beam.

FreeSpan™ castellated beam


To discuss the use of castellated and cellular beams on your project, please contact:

Joe Buntyn

District Sales Manager – Eastern U.S.

Direct: 772-530-0102


Chris Varner

District Sales Manager – Western U.S.

Main: 775-867-2130

Direct: 702-370-1222

Fax: 775-867-2140


Betty Corkwell

Engineering Manager

Direct: 260-868-6053

Fax: 260-868-6003



Download FreeSpan™ Literature:


Safety Data Sheets

Castellated Beams SDS (118kb pdf)

Steel Dynamics, Inc

New Millennium Building Systems is a wholly owned subsidiary of Steel Dynamics Inc.