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HDC Concentric Holdown

HDC

This product has been discontinued. Please see the HDU11 or HDQ8 as replacements.

The unique design of the HDC holdowns eliminate eccentricity. They install with Simpson Strong-Tie® Strong-Drive® SDS Heavy-Duty Connector screws (included) to reduce slip and provide a greater net section area of the post compared to bolts.

Material

  • 10 gauge strap

Finish

  • Galvanized strap, aluminum base

Installation

  • Use all specified fasteners. See Holdown and Tension Tie General Notes.
  • Install on concrete.
  • Sized for 2-2x, and 4x. Center 2-2x posts on holdown.
  • Uses Strong-Drive SDS Heavy-Duty Connector screws supplied with the holdowns to ensure proper fasteners are used.
  • Slot in the seat allows for 3/8" of adjustment perpendicular to plate.
  • Cut washer required between base and anchor nut. HDC10 models use narrow cut washer with outside diameter of 1 3/4".
  • Witness slot in the base to inspect the nut.
  • Maximum anchor bolt height above concrete is 2 1/8".
  • Aluminum standoff cannot be in contact with preservative-treated wood.
  • Strong-Drive SDS Heavy-Duty Connector screws install best with a low speed high torque drill with a 3/8" hex head driver.

Related Literature

Load Tables

  1. See Holdown and Tension Tie General Notes.
  2. The HDCs will be limited by wood compression capacity if installed on a sill plate. HDC10/22 will achieve an allowable load of 4005 lbs. on a DFL plate. HDC10/4 will achieve an allowable load of 4940 lbs. on a DFL plate, which does not take deflection into account. Full tension values apply when installed on a sill, deflections may be higher.
  3. Higher values may be obtained when HDC is not placed at an edge or with f'c concrete strength > 2500 psi.

Code Reports

Part IAPMO UES ER ICC-ES ESR City of Los Angeles State of Florida
HDCSee specific model numbers for code listings.
HDC10/22-SDS2.5 ESR-2330 ESR-2523 RR25720 FL10441
HDC10/4-SDS2.5 ESR-2330 ESR-2523 RR25720 FL10441
HDC5/22-SDS2.5 No code listing. Please contact us for test data.
HDC5/4-SDS2.5 No code listing. Please contact us for test data.

ESR-2523 is an Index of many of Simpson Strong-Tie Stamped and Welded Cold-formed Steel Products for Wood or Cold-formed Steel Construction

Drawings

Part Orthographic Perspective
HDCNone
High Wind-Resistant Construction D106: Holdowns: Typical HDC Installation with (2) 2x4 Studs
DWG DXF
HDC
DWG DXF
HDC10/22
HDC10/22
DWGDXF
HDC10/22 front view
DWG DXF
HDC10/22 left view
DWG DXF
HDC10/22 right view
DWG DXF
HDC10/22 top view
DWG DXF
None
HDC10/4
HDC10/4
DWGDXF
HDC10/4 front view
DWG DXF
HDC10/4 left view
DWG DXF
HDC10/4 right view
DWG DXF
HDC10/4 top view
DWG DXF
None
HDC5/22
HDC5/22
DWGDXF
HDC5/22 front view
DWG DXF
HDC5/22 right view
DWG DXF
HDC5/22 top view
DWG DXF
None
HDC5/4
HDC5/4
DWGDXF
HDC5/4 front view
DWG DXF
HDC5/4 right view
DWG DXF
HDC5/4 top view
DWG DXF
None