Why is there not a fine-thread screw longer than 1-1/2"?

We do not offer a fine-thread screw longer than 11/2" due to the fact that fine-thread screws have a smaller diameter and have the tendency to break off in harder woods. If you are working with hardwoods thicker than 11/2", you can set your jig up for 3/4" and use the 11/2" fine-thread screw. This will give you almost 1" into the mating piece, creating a strong joint.