Years ago, a black-and-blue thumb was the mark of all carpenters; now it’s the sign of someone who installs framing connectors. But soon it may be extinct altogether, thanks to Simpson’s Strong-Drive SD Screw for Structural Connectors. These 1/4-inch hex-drive galvanized screws are manufactured in two shank sizes: SD9 and SD10. According to Simpson, the SD9 is stronger than a 10d common nail, while the SD10 is stronger than a 16d common nail. Both sizes come in 1 1/2-inch and 2 1/2-inch lengths. A 100-count box of 1 1„2-inch SD10 screws costs about $12. Simpson Strong-Tie Co., 800/999-5099, strongtie.com.