Plaster and grout flow through the perforations in these washers to form a secure bond between the washer and the wall. Use them under drywall screws to fasten cracked, sagging plaster back onto lath and to secure wire mesh to backer board before installing tile.

Corrosion-Resistant Galvanized Steel—These washers combine the strength of steel with the rust resistance of stainless steel. They're an economical alternative to 18-8 stainless steel in wet and outdoor environments, but they won't hold up to salt water and chemicals.

Prongs—The prongs sink into lath, backer board, and other soft materials to hold the washer in place, so it won't shift during installation.