Page 34 of Wood Construction Connectors 2006 Catalog by Simpson Strong-Tie

For holdowns, per ASTM test standards, anchor bolt nut should be finger-tight plus to 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. NEW! The HDU series of holdowns are the latest in a long series of innovations from Simpson. These holdowns combine the advantages of low deflection and high capacity from the pre-deflected geometry with the ease of installation of Simpsons patented SDS screws. HDU SPECIAL FEATURES: Pre-deflected body virtually eliminates deflection due to material stretch. Uses SDS screws which install easily, reduces fastener slip, and provides a greater net section area of the post compared to bolts. SDS x2 screws are supplied with the holdowns. (Lag screws will not achieve the same load.) This ensures the proper fasteners are used and is convenient for the installer. No stud bolts to countersink at openings. MATERIAL: See table. FINISH: Galvanized INSTALLATION: Use all specified fasteners. See General Notes. Place the HDU over the anchor bolt. No additional washer required. To tie double 2x members together, the Designer must determine the fasteners required to bind the members to act as one unit without splitting the wood. See SSTB Anchor Bolts on page 33-34 for anchorage options. See Simpson Anchor Systems catalog for tested, load-rated retrofit anchors or request T-ANCHORSPEC for more information. CODES: See page 12 for Code Listing Key Chart. Model No. W Ga Dimensions Fasteners H B Anchor Bolt Number of SDS x2 Holdown Deflection at Highest Allowable Design Load HDU2-SDS2.5 6 HDU4-SDS2.5 10 Code Ref. .017 .049 DF/SP (133/160) SPF/HF (133/160) C L 160 Allowable Tension Loads HDU5-SDS2.5 14 HDU8-SDS2.5 10 20 .061 .037 HDU11-SDS2.5 10 14 14 14 1 30 .040 3 3 3 3 3 3 3 3 3 3 1 1 1 1 1 16 22 8 10 13 2625 4190 5430 8350 11275 2260 3600 4670 7180 9695 1. Allowable loads have been increased for earthquake or wind load durations with no further increase allowed; reduce where other load durations govern. 2. Loads are based on static tests on wood posts, limited by the lowest of 0.125" deflection, lowest test ultimate divided by 3 or the calculated values of the SDS x2 screws. 3. The Designer must specify anchor bolt type, length and embedment. 4. When using structural composite lumber columns screws must be applied to the wide face of the column. 5. Post design shall be by Designer. 6. SDS screws install best with a low speed right angle drill with a hex head driver. 7. Deflection values are valid for holdowns flush with and raised off of sill plate. 8. When using structural composite lumber columns, screws must be applied to the wide face of the column. HDU U.S. Patent 5,979,130 Vertical HDU Installation HDU may be installed raised off the sill plate with no increase in deflection values. RP6 Retro Plate The RP6 heavy steel plate fits on the outside of masonry buildings, helps tie the walls to the roof or floor structure with a diameter rod. FINISH: Simpson gray paint. Optional hot-dip galvanized finish; see Corrosion-Resistance, page 6-7, and specify HDG. MATERIAL: steel. Available with additional corrosion protection. Check with factory. INSTALLATION: Use a diameter rod. RP6 Typical RP6 Installation 35 Anchors HDU Holdown This product is preferable to similar connectors because of a) easier installation, b) higher loads, c) lower installed cost, or a combination of these features.

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