Recommendation for screws for end grain

[roy johnson]

Any recommendations on what type of thread to use when screwing into end grain: fine or course?

[Matt Woessner]

Roy,
Welcome to the Creek! I typically always use fine thread for hardwood and coarse for softwoods. Pre- drill your hole to avoid splitting. I am not sure if this is the correct way but I have not had anything fall apart!

[Jamie Buxton]

Long. Screws don't hold as well going into end grain as they do going into side grain. But notice the "as well" part of that generality. Use longer screws and you're okay.

[Brian Kent]

I am interested in this question. I imagine there would be a question of the direction of the pressure on the screw. Would the screw hold tension parallel to the end grain face (to keep the adjacent board from sliding) or perpendicular to the end grain face (to keep the adjacent board from pulling away). My wild, uninformed guess would be that for the first, the length of the screw would matter more than fine or coarse, and that for the second, coarse grain with perfect pilot hole would be best.

[Paul Symchych]

I also don't know the "correct" answer but think that longer must beat shorter if you really have to screw into end grain.
On occasion I have given what I think is something sturdier for the screw to bite into by drilling a hole at right angles to the screw and glueing a hardwood dowel about double the diameter of the threads into that hole. This way the threads had some cross grain to bite into. Maybe not necessary but it made me feel better.

[pat warner]

Anything with a twin thread. Test on scrap, but it is not uncommon to get 500# of pull strength from an inch & a half of thread in end grain with a no.10.
Given, of course, the correct pilot hole for the species.