Wow! These super long Timbrex ^TM screws will make you put away your hammer forever. With a self drilling point, these screws go into pressure treated lumber like a hot knife through butter. Plus, they won’t back out like nails, and they offer substantially greater holding power. Each has a #3 Square Drive on a 3/16” shank with 1/4” diameter threads and an oversize 5/8” diameter by 1/16” thick head, (dimensions are nominal). The threaded portion measures about 3 inches regardless of overall length, which is measured from the under side of the head. A special black epoxy corrosion resistant coating is extra slippery, and helps them pass a 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. Made in the USA.