by: Tim Tulethyme
I often see friends and fellow home-improvers using screws in their DIY efforts, and it never ceases to amaze me how hard some of these people find it to make a simple screw do what it's designed for. lets take a look at why. Of the two basic types of screw (Phillips cross head and the older 'traditional' slot head) the Phillips is gaining ground rapidly, due mainly to the fact that the extra cross-slot means you can apply more force and thus drive it into denser materials.
You need both types of screwdriver in your toolbox, because believe you me, nothing ruins a screwdriver faster than using it on the wrong type of screw! But what type of screw to use? Let's focus on common plywood for a moment - a material we often use at www.homeimprovementor.com because of its cheapness and versatility. You use number 8 screws for plywood up to 5/8th of an inch thick. Between 1/2 an inch and 3/8ths of an inch, you need a number 6. above that, try a number 4.
To join 2 pieces of wood with a screw, follow these easy steps. Firstly, make a mark where you plan to do the screwing. Position the pieces together and fasten with a clamp or your mighty left hand. Depending on the job, you may be able to use your body weight thru your knee to hold the bits in place. If neither of these methods are practicable, and you intend to sit several screws, use the first one as an effective 'clamp' by tightening it firm before you start the other screws.
Drill a quick pilot hole thru the bits. This pilot hole should be less than half the diameter of the screw you intend to insert. Handy www.homeimprovementor.com tip - if you want to gauge the depth your have drilled, place a bit of tape on the drill bit.
Countersink on the top piece of wood, so the job will look nice and sit flush. Insert the screw and tighten till the head is flush with the countersunk hole. Don't over-tighten or most modern self-tapping screws will start to 'chew up' the wood, and may even become loose!
To hide the screw head (especially important on jobs where security is an issue!) use a dowel plug. You'll have to drill the countersink a little deeper for this, of course. After inserting the plug, simply sand it down level with the board.
Handy tip to prevent splitting when screwing near the end of a board - drill a larger hole and insert a dowel, then screw into THAT instead of the wood itself. Easy huh? Till next time, happy screwing!