FINE-THREAD screw is used any time you’re driving the screw into a hardwood (i.e., oak, maple, walnut, cherry, hickory, etc.)
The COARSE-THREAD screw has a larger thread diameter and provides greater holding power when driving a screw into soft material such as plywood, particle board, MDF, melamine, and pine.
Our most common screw head type is the Maxi-Loc™ (SML) which is a washer head screw. The large bearing surface of the washer head is designed to seat securely in the bottom of the pocket, providing a tremendous amount of consistent clamping force on the joint line.
Our second head style is refered to as a pan head (SPS). The pan head is a slightly smaller head size that allows it to easily get below flush when joining 1/2" material. This is a particularly helpful when joining 1/2" to 1/2" plywood drawer boxes.(SML) COARSE WASHER HEAD SCREW
Use washer headed screw to keep head from crushing into bottom of pocket and going in deeper than expected. Great for soft wood and plywood.