In addition to typical high-low drive threads, GRK’s Caliburn concrete screws have a third groove that captures excess concrete dust so it won’t interfere with penetration. The screws have star-drive heads, an ACQ-compatible finish, and jagged cutting teeth along the threads that tap a hole that can be used again and again, says the manufacturer. Washer, pan, and flat-head screws come in lengths from 1 3/4 to 5 inches. A 50-count box of 2 1/4-inch screws lists for $28. GRK, 800/263-0463, grkfasteners.com
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