Driving screws should be among the easiest of all operations performed in the home or shop. But if you don't have the right screwdriver, it can be one of the most frustrating.
The basic screwdriver has four parts: handle, shank, blade and tip. Although wood-handled screwdrivers are available, those with plastic handles are preferred because of their greater strength and lower cost.
Screwdrivers come in a number of sizes, and tip designs correspond to several screw heads. Among the driver and screw types available are cross-slot varieties such as the Reed & Prince and Pozidriv designs, the square, recessed Robertson head and the star-shaped Torx pattern. But the overwhelming majority of screws you'll encounter are either cross-slot Phillips head or traditional slot-head.
Flat-tip screwdriver sizes are specified by the length of the shank and the width of the tip. In general, the longer the shank, the wider and thicker the tip and, accordingly, the larger the screw that can be driven. Lengths commonly range from 1 to 12 inches, with tip widths from 3/32 of an inch to half an inch. An assortment of half a dozen screwdrivers, including small, medium and large lengths of varied tip widths, will serve for most of the work you'll encounter.
Phillips-tip screwdrivers come in five sizes designated by the numbers 0 through 4, and in lengths from 1 to 8 inches. The standard slot-head screwdriver has a flared blade for extra strength. This feature, though, gets in the way when driving screws in counterbored holes. To solve the problem, cabinet- or parallel-tip versions are available.
For working in tight spaces, an offset screwdriver is the tool of choice. It's simply a steel rod bent at a 90-degree angle at each end, with the ends ground to fit slot- or Phillips-head screws. Ratchet offsets are also available for faster driving. The ratcheting action is particularly handy because the tip does not have to be removed from the screw for each partial turn. Offset drivers generally feature a different-size tip on each end.
When you don't have easy access to the screw pilot hole, a screw-holding screwdriver is the solution.
This driver has a gripping device at the tip so the screw can be positioned and driven with only one hand. Several types are available for use with slotted or Phillips-head screws.
Finally, when extra torque is required, a square-shank driver enables you to use a wrench to gain leverage.