The good news is that there is a screw for almost every job or material you are using:
> Board screw. This is specifically designed for wood or wood-type materials such as MDF or fiber board. It has a sharp point for easy starting and holds a grip inside the wood so it will not slip.
> Exterior screw. This is treated with an anti-rust coating to prevent corrosion or rust and is ideal for decking, joists or fines.
> Masonry or drywall screw. A masonry screw is specifically designed to cut into concrete and brick. A drywall screw has twin threads to allow for quick, easy installation.
> Security screw. This is designed to go in, but it is almost impossible to remove it. It's perfect for doors and locks.
> Self-tapping screw. Used mainly in joining pieces of metal, this screw cuts its own thread into the material.
Be sure to choose a screw that is long enough for the job. If you are joining two materials together, you want to choose something that is long enough to penetrate and grab both pieces. A screw that is too short may not be able to keep the materials fastened. A screw that is too long, on the other hand, may damage the wood on the other end.
You also want to choose the right diameter for the job as well. A screw that is too large may look unattractive or split softer, more fragile wood. On the other hand, a screw that is too small may not hold the materials well.
Screws also have their own types of heads. They can be flat, which will allow you to countersink the screw into the material; rounded heads, which tend to be more decorative; or flanged, which eliminates the need for washers. You also have a choice in what type of screwdriver you use on the screw. The two most common drives are:
> Slotted, which uses a standard blade screwdriver; and
> Phillips, which has a cross on the head.
Other, less common screw heads include square, hexagonal and Torx.
When choosing the right screw, make sure you know the exact purpose. The good thing is, you can rest assured that the right type of screw is out there.