Take a peek in any professional handyman's toolbox and you'll likely see a small variety of screwdrivers, some which don't even look like a screwdriver. The professional knows from experience that he may encounter any type of screw at any time, and to be unprepared could cost him money and make him appear less than professional. While do-it-yourself homeowners may not need to own the same variety of screwdrivers, it's not a bad idea to have some of the more common types on hand, including the more common sizes of the old stand-bys - the slotted and the phillips.

Sloted and phillips come in a variety of sizes, numbers 1, 2 and 3 being the most common. Of these, probably two thirds the screws you encounter will be size number 2 - the other third being number one, which is smaller, or number three, which is a step larger.

Square driver screws have become popular in home construction over the past ten years. The most common size for these is number 2, while the slightly smaller number 1 is sometimes used.

Torx drive screws are easily recognized by their six pointed star shape. Unlike the above mentioned screws, torx drive screws are common in many sizes, including from the small T-10, T-15, T-20, T-25, T-27, T-30 and the rather large T-40.

Security screws come in a wide variety, the most common probably being the slip-slot, also known as the one-way slot, often used for door locks. To drive these screws you only need the appropriate size slotted type screwdriver. To remove them, however, you'll need a special screwdriver with two hardened steel pegs at the end.

Other types of security screws have various shaped heads, including 5 point (similar to torx), two dimples or holes, hollow torx, which have a peg to prevent a standard torx driver from being used, and even S-shaped slots.

Most of the screws mentioned above, and their respective drivers, can be found at most hardware stores, home improvement outlets and tool suppliers. A practical set-up for the average household handyman or do-it-yourself homeowner would include the three common sizes of sloted and phillips screwdrivers, one screwdriver with interchangeable bits, such as are stored in the handle. It's not a bad idea to include a set of security bits.