Strong-Drive SDWH TIMBER-HEX HDG Screw

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$44.35 - $665.28


The SDWH Timber-Hex HDG screw is a 0.276"-diameter hot-dip galvanized screw suitable for marine and coastal applications. The SDWH Timber-Hex HDG screw has a SawTooth point and oversized integral washer that makes for fast installations; no predrilling or separate washer needed. Speed up your next pile job by replacing 3/4" and 5/8" HDG bolt/washer/nut assemblies (two screws for one bolt in many conditions) with the Strong-Drive SDWH Timber-Hex HDG screw. It is code listed under IAPMO-UES ER-192 and meets 2015 and 2018 IRC® and IBC® code requirements for several common wood framing applications.

Key Features

  • 0.276" shank diameter for heavy-duty structural applications
  • ASTM A153 Class-C hot-dip galvanized coating suitable for coastal and marine environments
  • SawTooth point design for fast starts and no predrilling
  • Oversized 0.93"-diameter integral washer eliminates the need for a separate washer
  • 3/8" hex drive for secure driving (replacement driver bit — BITHEXR38-134)
  • US Patent 9,523,383


  • Structural wood-to-wood, engineered wood, including ledgers and pile connections


  • Install Tip: For best results, use a minimum of 1/2" low-speed corded drill to install


Load Tables

SDWH Timber-Hex HDG — Allowable Single Shear and Withdrawal Loads

  1. All shear loads are based on full penetration into the main member. Full penetration is the screw length minus the side member thickness.
  2. Allowable loads are shown at the wood load duration factor of CD=1.0. Loads may be increased for load duration per the building code up to a CD=1.6. Tabulated values must be multiplied by all applicable adjustment factors per the NDS.
  3. For in-service moisture content greater than 19%: withdrawal CM=0.65; shear CM=0.70.
  4. When using tabulated single shear loads for multiple fasteners, minimum fastener spacing requirements: 8" end distance, 1 1/2" edge distance, 5/8" between staggered rows of fasteners, 4" between non-staggered rows of fasteners and 8" between fasteners in a row, multiply the table values by 0.80.
  5. Tabulated loads are for both parallel- and perpendicular-to-grain loading.
  6. Maximum withdrawal loads are based on full thread length penetration in the main member.
  7. SDWH271500G is not included in IAPMO-UES-ER-192.

SDWH Timber-Hex HDG — Stringer-to-Round Pile Connection Loads

  1. All tabulated values are based on double shear action with the same size and quantity of stringers on each side of the pile.
  2. Dimensions and allowable connection loads are based on notched piles that must accommodate the stringers with adequate bearing and no gaps. Notched piles shall not be notched such that more than 50% of the cross section is removed. Unnotched piles may be used providing the width and area of wood between the stringers and the fastener placement geometry is unchanged from the notched conditions.
  3. Allowable loads are shown at the wood load duration factor of CD=1.0. Loads may be increased for load duration per the building code up to a CD=1.6. Tabulated values must be multiplied by all applicable adjustment factors per the NDS.
  4. For in-service moisture content greater than 19%, use CM = 0.68.
  5. For conditions with stringers on one side only, use the longest screw length that does not extend beyond the opposite surface of the pile. Use one quarter of the loads shown for that length screw and stringer condition.
  6. Wood piles are SP. Wood stringers may be sawn lumber, glulam or SCL with minimum SG = 0.55 (or equivalent). For stringer widths at least 1.5" and less than 3.0" thick, use the table values for the conditions with a single 2x stringer on each side of the pile.
  7. For 14" diameter piles, use the same screw pattern as for the 12" piles. Loads for 14" diameter piles are based on single shear action.
  8. When a screw is loaded simultaneously in more than one direction, the allowable load must be evaluated using the unity equation: (Design Uplift ÷ Allowable Uplift) + (Design F1 ÷ Allowable F1) + (Design F2 ÷ Allowable F2) ≤ 1.0. The three terms in the unity equation represent the possible generated force directions. The number of terms that must be considered for simultaneous loading is the sole discretion of the Designer and depends on the method of calculating wind forces and the utilization of the screws within the structural system.

SDWH Timber-Hex HDG Screw — 2015 and 2018 IRC Compliant Spacing for a Sawn Lumber Deck Ledger-to-Rim Board

  1. SDWH27G screw spacing values are equivalent to 2015 IRC Table R507.2. The table above also provides SDWH27G screw spacing for a wide range of materials commonly used for rim board, and an alternate loading condition as required by some jurisdictions.
  2. Sawn lumber rim board shall be spruce-pine-fir, hem-fir, Douglas fir–larch, or southern pine species. Ledger shall be hem-fir, Douglas fir–larch, or southern pine species.
  3. Fastener spacings are based on the lesser of single fastener ICC-ES AC233 testing of the Strong-Drive SDWH27G screw with a safety factor of 5.0 or ICC-ES AC13 assembly testing with a factor of safety of 5.0. Spacing includes NDS wet service factor adjustment.
  4. Multiple ledger plies shall be fastened together per code independent of the SDWH27G screws.
  5. Rows of screws shall be vertically offset and evenly staggered. Screws shall be placed 1 1/2" to 2" from the top and bottom of the ledger or rim board with 3" minimum and 6" maximum between rows and spaced per the table. End screws shall be located 6" from the end and at 1 1/2" to 2" from the bottom of the ledger. For screws located at least 2" but less than 6" from the end, use 50% of the load per screw and 50% of the table spacing between the end screw and the adjacent screw, and for screws located between 2" and 4" from the end, predrill using a 3/16" drill bit.
  6. Structural sheathing between the ledger and rim board shall be a maximum of 1/2" thick and fastened per code.

See additional Load Tables, Technical Data and Installation Instructions for the Strong-Drive® SDWH Timber-Hex HDG screw


Extra Information

Simpson Strong-Tie
3.00 LBS