Log home builders first used this innovative timber screw to anchor one log to the next, but deck builders, landscapers, contractors, and others needing an easy driving, heavy duty fastener have quickly adopted it as their own. Extra deep threads maximize holding power in softwoods, while the diameter of the hex drive head is small enough to “bury” itself yet large enough to provide plenty of clamping force. Each screw has about 1-1/4" of thread. Select a screw that is approximately 2" longer than the thickness of the material you are fastening through for best results. A slippery black epoxy coating provides the corrosion resistance to pass a tough 25 cycle Kesternich corrosion test with less than 15% red rust. Use of these screws in Redwood or Western Red Cedar is likely to result in discoloration. 5/16 Hex Head. Made in the USA.