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HDB/HD Holdowns

HDB/HD

Simpson Strong-Tie offers a wide variety of bolted holdowns offering low-deflection performance for a range of load requirements.

The HD3B is a light-duty holdown designed for use in shearwalls and braced-wall panels, as well as other lateral applications.

The HD5B, HD7B and HD9B bolted holdowns incorporate the proven design of our HDQ8 SDS-style holdown and feature a unique seat design which greatly minimizes deflection under load. HDB holdowns are self-jigging, ensuring that the code-required minimum of seven bolt diameters from the end of the post is met. They can be installed directly on the sill plate or raised above it and are suitable for back-to-back applications where eccentricity is a concern. HDBs are designed to provide loads for intermediate-load-range shearwalls, braced-wall panels and lateral applications.

HD holdowns offer the highest allowable loads, providing high capacity for both vertical and horizontal applications. The HD12 and HD19 are self-jigging, ensuring that the code-required minimum of seven bolt diameters from the end of the post is met. They can be installed back-to-back when eccentricity is an issue.

Material

  • See table

Finish

  • HD3B/HD5B/HD7B/HD9B — galvanized; HD — Simpson Strong-Tie® gray paint; HDG available. For stainless steel options, see engineering letter L-C-SSHD.

Installation

  • Use all specified fasteners; see Holdown and Tension Tie General Notes
  • Bolt holes shall be a minimum of 1/32" to a maximum of 1/16" larger than the bolt diameter (per 2015 NDS, section 12.1.3.2)
  • Stud bolts should be snugly tightened with standard-cut washers between the wood and nut (BPs are required in the City and County of Los Angeles)
  • HD and HDB holdowns are self-jigging and will ensure minimum bolt end distance when installed flush with the sill plate
  • Standard-cut washer is required under the anchor nut for HD12 with 1" anchor and HD19 with 1 1/8" anchors

Related Literature

Load Tables

    These products are available with additional corrosion protection. Additional products on this page may also be available with this option, check with Simpson Strong-Tie for details.

  1. To achieve published loads, machine bolts shall be installed with the nut on the opposite side of the holdown. If reversed, the Designer shall reduce the allowable loads shown per NDS requirements when bolt threads are in the shear plane.
  2. Lag bolts will not develop the listed loads.
  3. HD19 with 1 1/4" anchor rod requires No. 1 or better post to achieve published loads.

Code Reports

Part IAPMO UES ER ICC-ES ESR City of Los Angeles State of Florida
HDSee specific model numbers for code listings.
HD12 ER-102 ER-143 RR25828 FL11496
HD19 ER-102 ER-143 RR25828 FL11496
HD3B ER-102 ER-143 RR25828 FL11496
HD5B ER-102 ER-143 RR25828 FL11496
HD7B ER-102 ER-143 RR25828 FL11496
HD9B ER-102 ER-143 RR25828 FL11496
HDBSee specific model numbers for code listings.

Drawings

Part Orthographic Perspective
HDNone None
HD12None None
HD19
HD19
DWGDXF
HD19 front view
DWG DXF
HD19 left view
DWG DXF
HD19 right view
DWG DXF
HD19 top view
DWG DXF
HD19
DWG DXF
HD3B
HD3B front view
DWG DXF
HD3B left view
DWG DXF
HD3B top view
DWG DXF
HD3B
DWG DXF
HD5B
HD5B front view
DWG DXF
HD5B left view
DWG DXF
HD5B top view
DWG DXF
High Wind-Resistant Construction D107: Holdowns
DWG DXF
HD5B
DWG DXF
HD7BNone
High Wind-Resistant Construction D107: Holdowns
DWG DXF
HD9BNone
High Wind-Resistant Construction D107: Holdowns
DWG DXF
HDBNone None