Screws, Drills, and Drivers

Since everyone isn't familiar with the nuances of power tools and various fasteners, we thought it would be a good idea to cover a couple of things.


The screws we use are #12 Square Drive, and we include a driver with each kit. These screws have a very high tested shear value, whereas many manufacturers use a generic number based on calculated values, which is much lower.  This really isn't good enough for an engineered structural product that requires of 5x safety margin. We're familiar with M25's, hex, tek's, and others. Some of these would require as many as fifty fasteners at significantly higher cost to get the test results and 5x safety margin that we achieved with thirty. Our suggestion if you 


If you use a Drill to drive square drive screws, especially in dense lumber, you may strip some. Rather than risk this it would be best to pre-drill the hole to relieve the tension on the tip as you install the screws. And we always recommend the use of a Driver rather than a Drill.

So the suggestions are three:

(1) Pre-drill the holes with an 1/8" drill bit.

(2) Use a Driver instead of a Drill.

(3) If the space is tight, with obstructions, or odd angles, it may be difficult to seat the seat the Driver into the square drive screw, and this will increase the risk of stripped screws. In this case, investing in Right Angle Driver attachment should really help. Most hardware stores have them, and of course Amazon, for under $30.

Here is a video about Drills vs Drivers