Tapcon Concrete Anchor Screw,Hex,1/4 in,PK100 3155407 - 1 Each

False advertising! The picture and title shows TapCon brand screws, but what is actually sent to you is a cheap Chinese knockoff with inferior threads sold under the name Simpson Stong Tie. The coating is not the same either, it looks like they just spray painted them blue to try and match the Tapcon color, but couldn't even get the color right. Without the notched thread design that TapCons have they will have a much harder time driving into concrete and you will twist the heads off. Sending them back!

First, let me answer a question you may have and save you the 30 minutes on hold I lost. It's a box of 100 (according to my 30 minute phone call). You'd think that would be a simple question to answer but, alas, it was not.Now, on to the review. I'm a professional railing installer. These screws are great for attaching things to brick, concrete, and stone IF, and it's an important "if", the force it encounters is in "shear" not "tension" (aka pull-out). They will withstand moderate pull-out tension but shouldn't be used for any safety-critical application where the screw relies on it's pull-out grip (such as overhead load support or anchoring railing posts to the floor). Lag shields or Redhead/sleeve anchors should be used where pull-out is high-load or safety-critical (and verify technical specifications for pull-out strength for your application and product choice).Installing is easy. Pre-drill with 3/16" masonry bit (hammer drills make it easier). When driving the screw, an impact driver works best. Be careful, if it stops driving in not to continue. You could snap the head off. The shaft can't be drilled out. If the screw binds up, be sure you pre-drilled deep enough and run the 3/16" pre-drill bit through the hole again to clean out dust and very slightly widen the hole. Be careful not to make the hole too large or the screw won't grip at all. Sneak up on it.