Hanging Shelves Studs

Craig Tiritilli is wondering if his hanging walnut shelves, and this things on them are going to bow the studs in his Dallas, TX home. Here's his situation:

"I have 4 pieces of solid walnut board. Each is 40" x 10" x 3".  I want to attach all four of them to a wall as shelves - vertically each about 15 inches apart.  I have L-shaped brackets that are plenty strong to hold the shelves and whatever I put on them.

But I am wondering if I attach them all to two studs if the studs can support that much weight.  Each shelf will weigh about 40 lbs on its own.  So that means the two studs would be holding about 160 pounds for all four shelves.

My question is - will the studs bow out or break from that much weight?"

Craig, the answer is no.

The weight of the shelves is, for the most part, being transferred down and not out.

There is a rotational force that's absolutely trying to pull the fasteners out of the stud, but that's going to rip the wood fibers along the shaft of the fastener long before the stud were to bow outwards.

If you put the wall stud horizontally like a beam, then you bet 160 pounds of weight at the center of the stud might crack it! But that's not what you're doing.