Page 35 of Wood Construction Connectors 2006 Catalog by Simpson Strong-Tie

36 Anchors PHD Predeflected Holdown HDQ8 Holdown Model No. Ga Dimensions Fasteners Allowable Tension Loads SPF/HF (133/160) Holdown 5 Deflection at Highest Allowable Design Load Flush W H B Anchor Dia. No. of Simpson SDS x3 Wood Screws PHD2-SDS3 14 3 9 2 1 10 3375 .063 PHD5-SDS3 14 3 11 2 1 14 4380 .077 PHD6-SDS3 12 3 13 2 1 18 5480 .068 PHD8-SDS3 deleted see HDQ8-SDS3 and HDU8-SDS2.5 Holdown 5 Deflection at Highest Code Ref. Allowable Design Load Raised .081 .077 .073 Allowable Tension Loads DF/SP (133/160) 3610 4685 5860 31, 98, 122 ,140 C L 1.Allowable loads have been increased for earthquake or wind load durations with no further increase allowed; reduce where other load durations govern. 2.The Designer must specify anchor bolt type, length and embedment. See the SSTB and SSTBL Anchor Bolts (page 33-34). 3.See page 21 and 29 for retrofit anchor bolt. 4.Loads are based on static tests on wood studs, limited by the lowest of 0.125" deflection, test ultimate divided by 3, or the wood screw value. 5.Deflection at Highest Allowable Design Load: The deflection of a holdown measured between the anchor bolt and the strap portion of the holdown when loaded to the highest allowable load listed in the catalog table. This movement is strictly due to the holdown deformation under a static load test conducted on a wood jig. 6. SDS screws install best with a low speed right angle drill with a hex head driver. Vertical PHD Installation (shown flush , touching sill plate) SDS x3 Screw US Patent No. 6,109,850 See screw info on page 20 7. SDS x3 screws are required for PHDs and HDQ8s. See T-HDLA for loads using shorter screws. 8. When using structural composite lumber columns, screws must be applied to the wide face of the column. 9. Tabulated loads may be doubled when the PHD or HDQ8 are installed on both sides of the wood member provided either the post is large enough or the holdowns are offset to eliminate screw interferences. 10. HDQ8s compression load requires an additional standard nut and square washer (BP -2) below the holdown. Maximum rod length is 6" from the concrete to achieve 7175 lbs using A36 steel. If rod length is longer, Designer needs to check rod for buckling capacity. 11. Maximum HDQ8 compression load is 6560 lbs. with 2-2x4 DF member. 12. Post design shall be by Designer. HDQ8 US Patents 6,006,487 and 6,327,831 HDQ8 Vertical Installation Model No. Ga W H B Anchor Dia. Allowable Compression Load 10 (lbs) No. of SDS x3 Wood Screws Holdown Deflection at Highest Allowable Tension Design Load Code Ref. HDQ8-SDS3 7 2 14 2 1 7175 20 8325 7210 .052 45, 106, 126 Allowable Tension Loads SPF/HF (133/160) Allowable Tension Loads DF/SP (133/160) C L HDQ8 may also be installed raised off the sill plate with no increase in deflection values. PHD5 (others similar) US Patent 5,979,130 Pressure-treated barrier may be required. Pressure-treated barrier may be required. The Predeflected Holdown (PHD) and HDQ8 are revolutionary developments in holdown connections. Predeflected during manufacturing, the PHD virtually eliminates deflection from material stretch. Each holdown uses SDS screws, which install easily, reduce fastener slip, and provides a greater net section area of the post compared to bolts. SPECIAL FEATURES: Wood screws reduce slip due to overdrilled bolt holes. Smaller centerline reduces eccentricity in the stud. No stud bolts to countersink. Fits easily in a 2x4 stud wall. MATERIAL: See table. FINISH: Galvanized. INSTALLATION: Use all specified fasteners. See General Notes. Place the PHD or HDQ8 over the anchor bolt. HDQ8: of adjustability perpendicular to the wall. HDQ8: Use in vertical and horizontal applications. Install Simpson's SDS x3 wood screws, which are provided with the holdown. (Lag screws will not achieve the same load.) For an improved connection, use a steel nylon locking nut or a thread adhesive on the anchor bolt. (No washer required.) See SSTB Anchor Bolts, page 33-34, for anchorage options. 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. For 2-2x and 3x sill plates use SSTBL models. To tie double 2x members together, the Designer must determine the fasteners required to bind members to act as one unit without splitting the wood. See Simpson Anchor Systems for tested, load-rated anchors and request T-ANCHORSPEC for more information. CODES: See page 12 for Code Listing Key Chart. Horizontal HDQ8 Installation Available with additional corrosion protection. Check with factory. 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.

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