How To Join Two Pieces Of Wood With Screws

Joining two pieces of wood together with screws is a very basic part of carpentry, or woodwork. If you cannot do a really excellent job at this, you will not be able to produce a professional looking piece of woodwork.

When two different pieces of wood are to be fixed together with screws, it is essential to use the correct size of screw. If it is too long, it will come through the surface of the second piece and ruin the finish and if it is too short, the fixing will not be strong enough. The correct screw length is calculated by measuring the depth of the top piece of wood and adding half the depth of the bottom piece to it. That means that the screw goes through the top piece but only half way through the underneath part.

Use a pencil to make a cross at the exact center point of where you want the screw to be. Use a drill bit which is about the same size as the width of the screw, but be careful that it isn’t any bigger or the screw may not grip hold of the wood securely. Drill right through the upper piece, starting at the point you made with your pencil. Then use a smaller drill and make a narrow pilot hole in the bottom piece of wood to take the screw. Don’t drill too far down; you just need to drill far enough to give the screw a start.

Countersunk screws have a shaped top or head, which goes down into the surface of the wood and if you intend to use these, fit your drill with a countersunk bit so that it gives you space to sink the head into when fixing the screw.

Pilot holes in the second surface are easy to make with a bradawl, but if the screw size is more that a size 6 (very small), use a drill bit.

When screwing wood together it is essential that all the screws are tightened up equally because differences in this can cause twisting of the wood because the tension is unevenly spread.

Selecting the right screws for a job is not always easy, especially if you are not an expert woodworker. Not all screws are suitable for wood. The countersunk screw with a cross slot head is the most common and most popular screw among carpenters and woodworkers. If you use the correct screwdriver with these screws, the screwdriver will not slip and damage the surface of the wood. Pozidriv screws allow you to use three different sizes of screwdriver and are often specially hardened.

If you are screwing together two pieces of chipboard, fiberboard, or similar, make sure that you use special chipboard screws which have very deep cut sharp edged threads that go all the way down the shank of the screw. These give very good grip and strength to the finished work and can also be used to fasten wood.