Tag Archives: nibs

Simpson Strong-Drive SDWS Timber Screw

Simpson Strong-Drive® SDWS Timber Screw

In yesterday’s article I discussed attachment of roof trusses in post frame building construction. In most cases, Hansen Pole Buildings utilizes Simpson Strong-Drive® SDWS Timber screws.
It was more than twenty years ago Simpson Strong-Tie changed fastening world with introduction of a heavy-duty structural connector screw used in wood construction as an alternative to bolts. This screw, SDS or Strong-Drive® screw, was first screw of its kind able to be installed without predrilling and get loads comparable to bolts.

Simpson Strong-Drive® SDWS Timber screws have been newly redesigned for faster starts and less torque while driving.

They are designed to provide an easy-to-install, high-strength alternative to through-bolting and traditional lag screws. Strong-Drive® SDWS Timber screw proves ideal for both contractors and do-it-yourselfer alike. Code listed under AAPMO USE ER-192 it meets 2012 and 2015 IRC® (International Residential Code) and IBC® (International Building Code) requirements for several common wood framing and engineered-wood applications.

Photo: Simpson SDWS – Simpson Strong-Tie

A new patented point called SawTooth™ improves SDWS performance in two key respects. First it grabs wood, helping screw start fast and drive quickly. Occasionally, an installer runs into a piece of wood harder than others or engineered wood with a hard surface. When a hard surface condition becomes encountered, most screw points will spin around upon surface, grinding away wood fibers until one thread can finally catch and begin to cut in. Simpson designed this SawTooth™ point with a sharp angle and serrated threads to penetrate wood quickly. Threads begin to work right away, pulling screw in faster without frustration of waiting for point to scrape open a hole.

A bold thread design provides superior holding power. Under-head nibs offer greater control when seating screw head. Large low-profile washer head provides maximum bearing area (3/4” head diameter). All SDWS screw heads have a size identifier, making inspections easy. 6-lobe T-40 drive reduces driver-bit cam-outs, resulting in easier installations and longer bit life.

A second performance enhancement made to SDWS screws was to lower driving torque. Let’s face it, some of these screws are long, and you don’t want to have to fight to keep from being thrown by a drill. SawTooth™ point has a cutting knurl built into screw point. This helps open a hole in wood to receive threaded length of screw all while it’s being pulled in by threads. Having a thread top knurl helps reduce shank friction. Result – a screw driving with less wear and tear upon installer, drill motor or drill battery.

Double-barrier coating provides corrosion resistance equivalent to hot-dip galvanization, making it suitable for certain exterior and preservative treated wood applications.

Watch the video here: https://www.youtube.com/watch?v=VpZmjgz2ckE