It depends on the materials and application. In general, size for size fine threads can be stronger. They have a larger center and more incline, which helps them to be stronger in tension and shear. That's provided the threads gain full grip. This isn't the case in soft materials like wood or man made wood products like particle board. To be equivalent to coarse threads, you often need longer length. The fine threads often foul in wood, if power driven they can strip. In most woodworking applications a coarse thread is more suitable. In shear, you may need to increase diameter compared to a fine thread. From underneath, in tension, the bigger the teeth, the better.