Concrete bolts

Concrete bolts

In cases where you can manufacture an antenna bracket, that takes care of that part. However, if you don't have a tower leg to attach to, but a building, wall or other concrete surface you need to use concrete bolts, or, anchors as they are called. First, drill the holes for depth and diameter you need for the bracket. You can purchase anchors at most local hardware stores. Here's some of the types available:










Here's a couple of applications they are used; on the top of a foundation (wall) and an "L" type bracket on a floor.




The Author prefer these two types: One's a "male" (or wedge bolt) and other "female" (drop-in). The third is a "third" choice if nothing else will work. The first type (bolt) is the most commonly used. You drill a hole size for the body of the bolt, not the threads, to a depth of the body of the bolt, not including the threads. Then you push the bolt in the (cleaned) hole, or tap it in with a hammer. When you try to pull it out it should not come out. Then when you tightened the nut, it will future wedge the bolt's body on the walls of the hole and stay there permanently.

First choice:




Second choice:




Third choice:








For the second (drop-in) type is drilled the same way, however it's best to use a tap/tool to open up the bottom of the body to press against the hole's wall. Then you insert a bolt and tight it (away from the hole) in the same fashion as the first type. This drop-in type has the advantage of mounting a bracket on the cornet of a building, so that if you have to remote the bracket for adjustments, will be easy. If the bolt type was sticking out you would not be able to remove the bracket.

When you buy them, the packaging should show what size diameter hole you need to drill. That will determine what bit size you'll need for the roto-hammer/drill for the holes in the concrete.

beside your local stories there are sources on-line which include the Red Head factory and W.W. Granger, Inc.








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