The Simpson Strong-Drive screw (SDS) is a 1/4" diameter structural wood screw ideal for various connector installations as well as wood-to-wood applications. It installs with no predrilling and has been extensively tested in various applications. The new SDS is improved with a patented new easy driving 4CUT tip and a corrosion resistant double-barrier coating. The patented 4CUT tip has a square core and serrated threads to reduce installation torque and make driving easier with no predrilling and minimal wood splitting. A new double-barrier coating finish provides corrosion resistance superior to hot-dip galvanization. Now one screw can handle interior, exterior and certain pressure-treated wood applications. 3/8" hex washer head is stamped with the No-Equal sign and fastener length for easy indentification after installation.