• 4" SDWH HDG Simpson hex timber screw
  • SDWH Timber Hex HDG screws by Simpson Strong-Tie
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SDWH Timber-Hex HDG Screw

SDWH Timber-Hex HDG Screw

Trusted by pros who build where weather never lets up. The SDWH Timber-Hex HDG screw keeps projects moving with reliable performance from dock to deck.

Key Features

  • Type 316 stainless steel for maximum corrosion protection.
  • No predrilling necessary in most applications.
  • Driver bit included (replacement driver bit — BITHEXR516-R1 or BITHEXR12-R1).
  • Can be used in ledger applications.
  • Unique “box” thread design with raised-ridge technology significantly reduces driving torque .
  • Hex-washer head provides large bearing area.

Applications

  • Structural wood-to-wood and engineered-wood connections, including ledger.

Product Includes

$61.00
$61.00
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Wooden deck construction with tools and materials on a wooden platform

Product Info

The SDWH Timber-Hex HDG screw is a 0.276"-diameter, hot-dip galvanized fastener designed for heavy-duty wood connections in marine and coastal environments. Featuring a SawTooth® point and an oversized integral washer, it installs quickly without the need for predrilling or a separate washer.

Replace 3/4" and 5/8" HDG bolt/washer/nut assemblies with the Strong-Drive® SDWH Timber-Hex HDG screw to speed up pile and framing work - two screws often replace one bolt in many conditions.

This screw is code listed under IAPMO-UES ER-192 and meets 2018 and 2021 IRC® and IBC® requirements for multiple wood framing applications.

Technical Specs

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. For minimum fastener spacing requirements for both side and main members, see the Spacing Requirements Figure and Table below.

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.

Screw Spacing Requirements

Table showing Screw placement requirements for SDWH heavy duty timber hex hdg screws

1. Table loads must be multiplied by adjustment factor of 0.80.
2. Table loads must be multiplied by adjustment factor of 0.89.
3. Table loads must be multiplied by adjustment factor of 0.78.
4. For axial loading only, use the following minimum dimensions: end distance = 4", edge distance = 1 5/8", spacing parallel to grain = 2 7/8", spacing perpendicular to grain = 2".

Diagram of SDWH Timber-Hex HDG Screw Spacing Requirements on a wooden background

Loads for Two-Sided, Stringer-to-Pile Connection

Table with pile capacity details including total shaft capacity, allowable connection loads, and other specifications for SDWH heavy duty timber hex hdg screws

1. Design of framing (stringers) and columns is by others.

2. Wooden piles and framing are southern pine (SP) or engineered wood products with minimum specific gravity or equivalent specific gravity of 0.55.

3. Use the screw lengths cited in the tables and details.

4. Tabulated loads are total load, not per side, and are based on double shear action with the same size and quantity of stringers on opposing faces of the pile.

5. Dimensions and allowable connection loads are based on notched piles that must accommodate the stringers with adequate bearing and no gaps.

6. Notched piles shall not be notched such that more than 50% of the cross section is removed.

7. Unnotched piles may be assigned notched pile loads if the unnotched-pile dimensions meet or exceed the maximum dimensions for the notched pile and fastener placement is the same.

8. Tabulated values shall be multiplied by all applicable service adjustment factors per the NDS. Allowable loads are shown with a load duration factor of CD = 1.0. Loads may be increased for load duration per the building code up to CD = 1.6. For service moisture content greater than 19%, use CM=0.70.

9. When the connection on an unnotched pile is simultaneously loaded in more than one direction, the allowable load must be evaluated using the unity equation: (Design uplift/Allowable uplift) + (Design lateral/Allowable lateral) + (Design vertical/Allowable vertical) ≤ 1.0. If notched piles are used, the last term is zero.

10. For stringer thickness at least 1.5" and less than 3", use the table values for the conditions with a single 2x stringer.

11. Butt loads are based on all stringer members butted. For multi-ply stringers where one stringer is continuous, use the tabulated loads in the “Continuous and Lap” column.

2024, 2021 & 2018 IRC Compliant Spacing for a Sawn Lumber Deck Ledger-to-Rim Board

Table detailing specifications for rim boards with various dimensions and plate thicknesses.

1. SDWH27G screw spacing values are equivalent to 2024/2021/2018 IRC Table R507.9.1.3(1) and 2015 IRC Table R507.2. The table 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. Screws shall be placed 1.5" to 2" from the top and bottom of the ledger or rim board with 3" minimum and 6" maximum vertical distance between fasteners with horizontal on-center spacing per the table. End screws shall be located 6" from the end and at 1.5" 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.