Made of zinc-plated steel, a pair of these blind shelf supports will invisibly hold a 1" or thicker shelf. Each mounting plate is anchored to the wall studs with two flat-head screws, and the projecting 5" long hex posts slip into 7/16" holes drilled in the back side of the shelf. Even if your holes end up slightly undersize, the corners of the hex post will cut their way in.
The design ensures that the alloy steel coupling screws remain tensioned between the posts and inserts in the plates, yielding a respectable capacity of 100 lb for a 4" deep shelf and up to 50 lb at 8" deep*.
Additional supports are sold singly for increasing load capacity on shelves long enough to span more than two studs; each extra support adds 50 lb more capacity at 4" deep, and 25 lb more at 8" deep*.
The simple instructions included make installation a snap.
Made in Canada.
* These capacity ratings are based on evenly distributed loads. Keeping the load more toward the rear of the shelf will increase the capacity and decrease deflection.
Note: For shelves narrower than 5 1/4", you will have to cut some of the non-threaded end of the hex post (with a hacksaw), so the posts are roughly 3/8" shorter than the shelf's depth.