HHDQ Heavy Holdown, Quick-Install
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The HHDQ is designed for extra-high loads and provides ease of installation. This heavy holdown comes with Strong-Drive® SDS Heavy-Duty Connector screws, which install easily, reduce fastener slip and provide a greater net section than bolts. The HHDQ is installed directly on the sill plate and is suitable for back-to-back applications where eccentricity is a concern.
- Strong-Drive SDS Heavy-Duty Connector screws are supplied with the holdowns to ensure proper fasteners are used
- Screws may be installed either flush or raised off the mudsill without a reduction in load value
- No stud bolts to countersink at openings
- Body: 7 gauge, washer: 1/2" plate
- Simpson Strong-Tie gray paint; HHDQ11 — available in stainless steel
- See General Notes for Holdowns and Tension Ties
- Strong-Drive SDS Heavy-Duty Connector screws install best with a low-speed, high-torque drill equipped with a 3/8" hex-head driver
- No additional washer is required
- HHDQ14 requires a heavy-hex anchor nut (supplied with holdown)
For stainless-steel fasteners, see Fastener Types and Sizes Specified for Simpson Strong-Tie Connectors.
- HHDQ14 requires a heavy-hex anchor nut (supplied with holdown).
- HDQ and HHDQ installed horizontally achieve compression loads with the addition of a standard nut on the underside of the load transfer plate. Refer to ICC-ES ESR-2330 for design values. HDQ8 requires a standard nut and BP 7/8-2 load washer (sold separately) on the underside of the holdown for compression load. Design of anchorage rods for compression force shall be per the Designer.
Code Reports & Compliance