– And today's video how to choose the right size pre drill bit, why it's important to pre drill and a few other helpful tips. Pre drilling is done to remove the material where the shank of the screw or nail for that matter, will eventually go. Pre drilling makes it much easier to install the screw and prevents possible damage. If pre drilling doesn't happen then the wood will have to compress and move out of the way of the screw. And with softwoods like pine, that's generally not a problem, but when it comes to hardwoods like Oak which is much more dense, the wood fibers have a harder time compressing making it much more difficult to install the screw or nail. Moreover, if that hard material can't compress enough then you risk splitting or cracking or even breaking the screw off itself. Therefore, in order to prevent those things from happening you're gonna wanna pre drill. And if necessary, you're going to want to countersink so that the screw head is flush to the surface. To get the right drill bit size, most screws have a number associated, depicting their size, like a number three or number 10. There are hundreds of sizing charts online. So just download one and use it by simply matching the screw number with the right size pre drill bit. Another less precise way is to match up the shank size with the bit size. You can do this by overlaying the bit on the screw and visually matching the shank to the proper bit. Just make sure that the bit only removes the shank diameter because it's very important that you leave enough material for the threads to do their job. As a side note, you'll see on most sizing charts that they give a number for softwoods and for hardwoods. Again, because of the compression factor being different for each material. Let's look at a few examples of what happens when you pre-drill and when you don't. The first screw is going into softwood without pre-drilling and you can see that the screw starts really easy, and it doesn't seem to have really any problems. But if we look on the backside, you can start to see some minor splitting. This time if we pre drill, the screw goes in incredibly easy, and the back has no signs of splitting. If we move over to hardwood, you can see that without pre-drilling the screw is extremely difficult to start and to install. Plus the wood is mushrooming or mounding up at the entrance. This screw is far enough away from the edge that there's not a lot of noticeable splitting even on the back, but don't let that fool you. Over time a split can become noticeable, but if we move that same screw to the edge, look and listen to what happens. (wood cracking) now this time if we pre drill, the wood will not compress or expand as much, so no splitting or cracking. And the threads of the screw are cutting nicely and quickly through the material. In addition, you can always add some screw wax to the threads, which reduces the resistance and makes it even easier and less work on you to install. And I know what some of you might be thinking, you should just use a drill to put those screws in. And drills are great and I use them all the time, but sometimes it's hard to tell when the drill is working harder than you'd like and putting too much strain on the screw and the wood. So when it comes to projects that really matter, drop the drill and grab the screwdriver. The last thing I want to bring to your attention is not all screws need pre drilling. There are many screws on the market that are self-tapping, or self drilling, meaning that they cut a hole as they're being installed. Grain direction, moisture content, and many other factors also come into play here, but let's just keep it simple, when in doubt and when the project really matters, pre drill. Well that's it for today's video hit the thumbs up if it's been helpful, subscribe to the channel if you're not already, leave me a comment below and I'll see all your smiling faces next Tuesday. (upbeat music)
