A number of specialty fasteners can be used in place of slot and Phillips head screws. The objective is to improve transfer of torque from the screwdriver to the fastener, minimize slip, and enable installation on robotic assembly lines.
The Posi-Drive™ screwdriver is similar to a Phillips but with a tip that is flatter and blunter. The squared tip grips the screw head and slips less than an equivalent Phillips screwdriver. A Torx® fastener is often used to secure headlight assemblies, mirrors, and brackets. Not only does its six-prong tip sustain greater torque and less slippage, but it also provides a measure of tamper resistance. It requires a Torx® screwdriver or bit to remove and install them.
• Use screwdrivers only for turning screws. Using them as punches or prybars breaks handles, bends shanks, and dulls and twists the tips.
• Abuse makes them unfit to tighten or loosen screws safely.
• A slotted screwdriver tip can easily be dressed to its original shape. Never grind the tip, because excess heat will destroy the temper. Always file by hand; you will have more control on the shape of the tip and not remove the temper.
• If the screwdriver blade fits the screw slot properly, you will produce maximum torque with minimum effort. A blade tip that does not fit properly will damage not only the screw slot but perhaps the tip itself.
• It is a good rule to keep your other hand clear when applying force to any type of screwdriver.
• Always have the screwdriver and the screw correctly lined up. You cannot get a good grip in the slot if the tip is held at an angle.
• Screwdrivers designed for use with wrenches (for high torque application) have either a square shank or a hex bolster at the handle to withstand the application of extra force.
• Do not hold components in your hand while turning fasteners with a screwdriver. Put the work on a bench or in a vise to avoid the possibility of piercing your hand with the screwdriver tip.
• When working around anything electrical, use a screwdriver with an insulated handle and shank to avoid shock and short circuits.