Basements, Attics and Crawl Spaces - Masonry Screws

Now I know that typically speaking with masonry any sort of screw that you put into a cement wall requires a plastic anchor. Through a suggestion while at menards though I was recommended to buy some masonry screws that supposedly dont need an anchor. When I went home to use the screws they spin loosely into the wall and don't grip. I tried sending in a pilot hole and I am using the right size masonry bit for what it says on the box for the screws. Any suggestions on what I'm doing wrong here? Or is it maybe the screws? I am using a standard drill though as opposed to a hammer drill but I don't think this is an issue as it drilled the pilot hole fine. Any help would be greatly appreciated.

Are you using tap cons?
Generally they work well. Are you sure you are using the correct size bit? are you accidently wallowing out the hole as you drill it?

What are you drilling?? Some masonary materials drill better than others. If you hit a stone, the bit will tend to wander. Sorry for English measurements, but a 3/16 tapcon needs a 5/32 masonary bit, 1/4 screws takes a 3/16 bit. A standard drill will often walk in the hole, making it oversize. Hammer drills make a more true hole. If the hole is the right size, they work well, if slightly oversize, you already know.

Are you drilling solid concrete, concrete blocks, or cinder blocks. The latter might be a peoblem.

Bud

Wow, thanks for the responses. I am using the Tapcon screws. The screw is 3/16ths and I am using the recommended 5/32nds masonry bit. Ha, even went with the recommended Tapcon bit. What I'm doing is I built a shelving unit to hang my wood clamps on but putting it up in my basement. The wood shelf that I'm trying to hang on the wall is about an inch thick where it screws in. I wonder now if I might have been wallowing out the hole on accident. As far as what kind of cement I'm assuming its solid concrete. I'm new at this so I think I'm right but could very well be wrong. There are no pieced together blocks like I would assume there would be with using concrete blocks or cinder blocks. Please correct me if I'm wrong on that though.

Does sound like solid concrete. How long are your screws? Also, when you install them through the wood, first open the hole on the wood to be a clear hole, 3/16ths. That way you are not fighting the threads in the wood.

Bud

It is difficult what your question actually is, but you are apparently having some problems.

You asked about "masonry screws" which is not what should be be used on concrete (which is not cement, but a mixture of cement, water and very strong rock aggregate).

If you are dealing with masonry, which consists of mortar and masonry units (usually concrete block/brick of clay brick) that requires a different situation.

In masonry, the screws should be into the mortar, which is more predictable and not the clay brick, which is highly variable, hard to drill into and very easy to split or crack.

If you are going into real concrete, you should have an accurate hole (diameter and location) that is not oversized by a drill bit wandering. The holes should be full depth and the dust removed to allow the screw to enter. Do not over-tighten, since that just causes a loose screw and reduced capacity.

The length is 1 and 3/4 inch. Good thinking on the wood portion. Now I know somebody already mentioned a hammer drill being more accurate but I don't know about purchasing one since I'm unsure how much use it'd get. Possible I guess. Any suggestions on making a more accurate hole with a standard drill? Can it be done?

It can be done. Make sure you are using a sharp bit. Make sure you don't go full speed because the bit will heat up and bend. Make sure that the chuck is not bent. I have a few drills that are bent one I dropped off a boom lift 35 feet up hit concrete floor. It still works but I can't use it when the hols size counts.

IMO the 3/16" tapcons are worthless and almost always strip because the threads are so fine and the hole has to be so precise.

I have always had better luck using their 1/4" screws instead. More thread to bite into the cement.

Additionally, you want a minumum of 1" of screw biting into the cement, so if your material is 1" thick, you may need a 2 1/4" long screw. I'm guessing this is one reason your screws won't bite... they aren't long enough. In addition to not using a hammer drill and having a rounded out hole.

Your length may be the issue, since the end of the screw is tapered you have less than 1/2" to secure to the concrete. One inch of wood and a 1 and 3/4" screw if I am following you correctly. Even if the wood is really 3/4" it could use a longer screw. I'd go 2 and 1/2", that way any wobble would have straightened out and the bottom of the hole will be solid.

Bud