Shear Anchorage: OMFAB Anchorage Assembly
Simpson Strong-Tie offers the pre-engineered OMFAB anchorage assembly as an alternative to the OMFSL. Pre-engineered solutions include additional concrete reinforcement to provide a complete solution meeting the 2006 and 2009 International Building Code requirements for both tension and shear. These solutions require that the column be installed in from the edge of the concrete, on either a slab or curb, and develop the full allowable shear capacity of the frame.
OMFAB anchorage assemblies are fully assembled and include a template which allows easy positioning and attachment to forms prior to the pour. Inspection is easy since the head is stamped with the “No Equal” (≠) symbol for identification, bolt length, bolt diameter, and optional “H” for high strength (if specified).
Installation: Concrete must be thoroughly vibrated to ensure full consolidation of the concrete around the assembly.
OMFAB6
Use for 6" columns
OMFAB9
Use for 9", 12", and 15" columns
Not available in hot dipped galvanized; use OMFSL.
Plan View –
Curb/Stemwall

Section at
Curb/Stem
Plan View – Slab on Grade

Section at Slab on Grade
- Anchorage solutions applicable to wind design and seismic design in Seismic Design Category A, B, or C using R ≤ 3.0. For designs based on R = 3.5, see Table 3.2.
- Solutions are based on embedment in concrete with minimum f'c = 2,500 psi.
- Solutions are base on standard strength OMFAB_-__-KT anchorage assembly, except shaded values, where high strength OMFAB_-__HS-KT anchorage assembly is required.
- OMFAB tied anchorage solutions require Strong Frame column to be located in from the edge of slab. For solutions with column at edge of slab, use OMFSL.
- Ties, hairpins and vertical reinforcing shall be ASTM A615 or A706, Grade 60 reinforcing, and are not supplied by Simpson Strong-Tie. Tie and hairpin installation is shown above.
- Stemwall/Curb tied anchorage solutions may also be used for slab on grade installations.
- Anchorage solutions are based on maximum shear and tension reactions resulting from the tabulated allowable shear load applied to the frame in combination with the gravity loads noted. For frames with an applied shear less than the allowable load or with additional uplift, see Table 3.2.
- Also see tension anchorage solutions.
- Seismic includes designs in all Seismic Design Categories and designs using R ≤ 3.0 or R = 3.5.
- Solutions are based on embedment in concrete with minimum f'c = 2,500 psi.
- OMFAB tied and hairpin anchorage solutions require Strong Frame column to be located in from the edge of slab. For solutions with column at edge of slab, use OMFSL.
- Ties, hairpins and vertical reinforcing shall be ASTM A615 or A706, Grade 60 reinforcing, and are not supplied by Simpson Strong-Tie. Tie and hairpin installation is shown above.
- Hairpins must be spaced at 2" o.c. (See above.)
- Stemwall/curb tied anchorage solutions may also be used for slab on grade installations.
- To select anchorage solution, use shear reactions from Maximum Column Reactions in allowable load tables, or column shear reactions calculated in accordance with allowable load tables, footnote 4.
- LRFD capacities may be obtained by multiplying tabulated values by 1.6 for wind or by dividing tabulated values by 0.7 for seismic.
- Solutions are base on standard strength OMFAB_-__-KT anchorage assembly, except shaded values, where high strength OMFAB_-__HS-KT anchorage assembly is required.
- See tension anchorage solutions for additional anchor strength requirements. Use high strength OMFAB_-__HS-KT anchorage assemblies where required by either tension or shear anchorage.
- Also see tension anchorage solutions.