Simpson Strong-Tie Strong-Drive TIMBER Screw

The ultimate screw for extra-strength applications.

Sponsored by Simpson Strong-Tie®

As many of you know, I’ve been rebuilding our family cottage for a few summers now. I’ve doubled the floor space and raised the roof, and I’m in the middle of building two decks. During this project, I’ve become a huge fan of big structural screws. Not ordinary deck screws, but the big honkers that can replace bolts and lag bolts. One of my favorite structural screws is the Simpson Strong-Tie Strong-Drive SDWS TIMBER Screw.

Simpson Strong-Tie® Strong-Drive® TIMBER Screw
Driving a Strong-Drive TIMBER Screw to attach a post to a deck railing.

These structural screws, with their aggressive thread and narrow shank, drive fast (no pilot hole necessary!) with an ordinary 1/4-in. impact driver. (If you’re installing lots of them, though, a larger driver is better.) The wide flat head is like a washer, stopping the screw when it’s flush and keeping it from being pulled down into the wood. The screws are coated with some kind of miracle material that the manufacturer claims is equivalent to hot-dip galvanized, so you can use them outdoors and in treated wood. (And since this cabin is permanently damp, everything has to be rustproof and rot-proof!) I prefer the washer-head style, which you drive with a big T-40 hex bit, though the same screw is available in a hex-head drive. The SDWS Timber screws come in lengths from 3 to 10 in. long.

Simpson Strong-Tie® Strong-Drive® TIMBER Screw
Comparison of a Strong-Drive TIMBER Screw and a traditional ledger screw. Notice the larger head, hex drive, more aggressive threads and self-starting tip.

So what are these screws so great for? Well, installing ledger boards is the classic application. They are SO much faster than lag bolts and through bolts, mostly because no predrilling is required. In a big remodel, though, like the one I’m doing, there are dozens of situations where you need to attach doubled-up framing, or when you need extra strength (like bracing posts) or any number of “how-do-I-do-this?” situations. The longer lengths, 5 in. and up, are especially handy.

You can buy or order Strong-Drive SDWS Timber Screws at most lumberyards that cater to professionals. Get more info about Simpson Strong-Tie.

— Ken Collier, Editor in Chief

Simpson Strong-Tie® Strong-Drive® TIMBER Screw
Strong-Drive TIMBER Screw showing six-lobe driver bit and recess.

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