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Strong-Drive® SDWF Floor-to-Floor Screw

SDWF Product Image

The Strong-Drive SDWF Floor-to-Floor screw is designed to simplify the wind-uplift restraint connection while providing superior performance over the life of the structure. The unique design of the SDWF enables it to attach upper and lower walls together from the top, spanning the floor system and providing an easy-to-install connection within the continuous uplift load path of the structure.

The innovative Take-Up Washer (TUW) plays a key role in the long-term performance of the SDWF when installed between the screw head and the sole plate of the upper floor. As the structure settles because of shrinkage and construction loading, the threaded portion under the head of the screw ratchets up through the tabs of the TUW, which is fastened with Simpson Strong-Tie Strong-Drive SD screws. The interlock between the tabs of the take-up washer and the threads under the head of the SDWF prevent the screw from sliding back under load, providing a simple yet reliable means of shrinkage compensation up to 3/4" per story.


Light Duty Drill

Light Duty Drill


SD #9 Screw

SD #9 x 2 1⁄2"



SDWF Installation, Step 1


SDWF Installation, Step 2


SDWF Installation, Step 3


SDWF Installation, Step 4


SDWF Installation, Step 5