5/8" x 7" Stainless Steel Wedge Anchors for Concrete - Heavy Duty Expansion Bolts (12 Pack) - Perfect for Securing Fixtures, Railings, and Structural Supports in Construction Projects

The idea behind a wedge anchor is that you shove something down a tight hole that expands at the bottom and holds the whole anchor in place. No adhesive or concrete is needed. If the material you drill into is crumbly, soft, or weak a wedge anchor is a poor choice since it will have nothing secure to bite into when it expands. Most wedge anchors I've used were not made of stainless steel and they worked fine. However, I had an installation close to a spa with external fountain that would routinely get wet. I didn't want the anchors to corrode away and make a problem in the future.The manufacturer's video shows the four step process for installation, in a panel at its end. Do not drill a hole bigger in diameter than needed because expansion at the bottom is not forgiving - you only get so much and then there is no grip to be had. I use an SDS hammerdrill and work carefully to drill straight and on-center so the hole doesn't widen as I go. The hole has to be deep enough to accept some of the threaded section of the anchor since the anchor will be lifted back out of the hole as the nut is tightened. The deep end will snag from having been tapped in with a hammer, and as the nut is turned the deep end of the anchor mushrooms out to make the secured physical connection. The rest of the anchor is not tight with the hole you just drilled, so water and dirt can get in. I like to partially fill the hole with silicone so it gets sealed from the top. The threaded part of the other end of the anchor will stick out past the nut. With threadlock compound on the threads of the nut I don't get concerned the nut will back off and I cut or grind the excess thread off for a cleaner installation. Of course, the nut and washer are on top of what is being anchored down, and the threaded end of the anchor is put through a mounting hole before the washer and nut go on.This is where you have to be careful. If the substrate, probably concrete, has rebar or metal mesh, or if what you are securing is other than stainless steel, where two dissimilar metals touch you will set up an electrolytic cell. Being in a wet area, that cell will be active for the life of the installation. (Not in a wet area? Then why did you use a stainless steel anchor?). Electrical current will be created and flow between the metals and across the moisture, electrolysis will occur, the stainless steel will survive, but the rebar or the equipment you are securing will corrode to a powder. In other situations it may be good enough to coat or paint where the dissimilar metals touch so no water can reach it and no current will be creatd and flow. However, in a wet area, especially on concrete or masonry, water will diffuse through the substrate and will always be present even if you paint or coat the physical connection. Don't mix metals. If you are securing a galvanized steel framework, get a carbon steel wedge anchor. If you're securing stainless steel equipment, use this stainless steel wedge anchor.Used in the right application and installed properly, this concrete anchor is very good. It is priced well, too.