These didn't work out for me, but I'm not sure why. I used a similar product - a red head sleeve anchor tightened by a nut, to secure some 2x4's to a brick wall and they worked perfectly. I bought this product to secure some plywood to the same wall, wanting to countersink the head. But of about 10 installed, only two grabbed and tightened. It may have been the way I installed them, or the very old brick may have been too soft, so I'm hesitant to fault the product. They just didn't work the way I hoped.