Page 37 of Wood Construction Connectors 2006 Catalog by Simpson Strong-Tie

38 Anchors HDA/HD Holdowns * Typical HD5A Tie between Floors Vertical HD15 Installation HD5A (HD2A similar) Vertical HD5A Installation with SSTB anchor bolt. Washers are not required at the base. HD10A (HD6A, HD8A and HD14A similar) * To achieve table loads, the minimum bolt end distance is seven bolt diameters. This distance is designed into holdowns. BPs are required by the City of Los Angeles. Check with your local building code on usage. (NDS Section 11.1.2.3 requires a metal plate, metal strap, or minimum of a standard cut washer.) Pressure-treated barrier may be required. Holdowns are used to transfer tension loads between floors, to tie purlins to masonry or concrete, etc. Use HDAs and HDs for overturning requirements and other applications to transfer tension loads. All HDAs and the HD15 are self-jigging, ensuring code-required minimum 7 bolt diameter spacing from the end of the wood member to the center of the first bolt hole. HD6A, HD8A, HD10A and HD14As seat design allows greater installation adjustability. An overall width of 3 for the HD6A, HD8A and HD10A, and 3 for the HD14A provides an easy fit in a standard 2x4 stud wall. HDA SPECIAL FEATURES: Load Transfer Plate eliminates the need for a seat washer. Fewer inspection problems. MATERIAL: See table on opposite page. LOADS: See table on opposite page. FINISH: HDAs galvanized. May be ordered HDG, check with factory. HD15 Simpson gray paint. INSTALLATION: Use all specified fasteners. See General Notes. Contact engineered wood manufacturers for connections that are not through the wide face. For an improved connection, use a steel nylon locking nut or a thread adhesive on the anchor bolt. Bolt holes shall be a minimum of to a maximum of larger than the bolt diameter (per 2001 NDS, section 11.1.2). Standard washers are required between the base plate and anchor nut (HD15 only), and on stud bolt nuts against the wood. The Load Transfer Plate is an integral part of the HDA Holdown and no washer is required. See page 23 for BP/LBP Bearing Plates. See SSTB Anchor Bolts, Simpsons Anchoring Systems and Additional Anchorage Designs for anchorage options. The Designer may specify any alternate anchorage calculated to resist the tension load for a specific job. Locate on wood member to maintain a minimum distance of seven bolt diameters, distance is automatically maintained when end of wood member is flush with the bottom of the holdown. Stud bolts should be snugly tightened. 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. For additional information, request T-HD. 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. 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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