HDQ8-SDS3 Holdown

*For further description please see Simpson Strong-Tie Wood Construction Connectors Catalog.

**Click Load Table icon for size & fastening requirements.

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HDQ8/HHDQ Holdown

The HHDQ series of holdowns combines low deflection and high loads with ease of installation. The unique seat design of the HDQ8 greatly minimizes deflection under load. Both styles of holdown employ the Simpson Strong-Tie® Strong-Drive® screws (SDS) which install easily, reduce fastener slip and provide a greater net section area of the post when compared to bolts. They may be installed either flush or raised off the mudsill without a reduction in load value.

Special Features:

•Uses SDS screws which install easily, reduce fastener slip, and provide a greater net section area of the post compared to bolts.

• SDS screws are supplied with the holdowns to ensure proper fasteners are used.

•No stud bolts to countersink at openings.

Material: HDQ8—7 gauge; HHDQ - Body: 7 gauge, washer: 1/2" plate

Finish: HDQ8—Galvanized; HHDQ—Simpson Strong-Tie® gray paint

Installation:

•Use all specified fasteners. See General Notes.

•For use in vertical and horizontal applications.

• No additional washer is required.

•To tie multiple 2x members together, the Designer must determine the fasteners required to join members without splitting the wood.

•See SB and SSTB Anchor Bolts for anchorage options.

•SDS screws install best with a low speed high torque drill with a 3/8" hex head driver.

•Refer to Anchor Designer Software™ for ACI 318 for anchoring solutions.

HDQ8:

• 5/8" of adjustability perpendicular to the wall.

•See SSTB Anchor Bolts for anchorage options. For 2-2x and 3x sill plates use SSTBL models. The Designer may specify any alternate anchorage calculated to resist the tension load for a specific job. Anchorage length should take the bearing plate/washer height into account, to ensure adequate length of threads to engage the nut.

HHDQ11/14:

•No additional washer is required.

•HHDQ14 requires a heavy hex anchor nut (supplied with holdown)

• See SB Anchor Bolts for anchorage options

For holdowns, per ASTM test standards, anchor bolt nut should be finger-tight plus 1/3 to 1/2 turn with a hand wrench, with consideration given to possible future wood shrinkage. Care should be taken to not over-torque the nut. Impact wrenches should not be used.