Screwdrivers

The screwdrivers are used for loosening or tightening screws or screw head bolts. The handles are usually made of wood or plastic. There are different types of screwdrivers available based on its shape, blade type and blade length.

The main types of screwdrivers are given below.

Common Screwdriver: It is a flat bladed type screwdriver and is used only where slotted head screws or fasteners are found on aircraft. The blade is made up of high carbon or alloy steel. The end is being ground flat to fit the slot cut in the head of the screw.

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Ratchet Screwdriver: It is one of the useful tools with a user-friendly selection of bits in a screwdriver set. It has a selector that allows the ratchet to be locked and removed.

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Pump Screwdriver: It is operated based on the Archimedes principle. When the handle is pumped, the screwdriver turns accordingly.

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Offset Screwdriver: It has the blade at right angles to the shaft and is used when vertical space is limited. By using alternate ends, most screws can be seated or loosened even when the swinging space is limited.

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Watchmaker’s Screwdriver: It has a long thin blade with a flat plastic handle and used for smaller screws such as in electric work.

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Electric Screwdriver: These are usually re-chargeable and are battery-operated. The electric motor can be controlled in such a way it can provide varying speed and torque output. The screw bits are supplied in different shapes and sizes that fit into an adapter.

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The following are some of the screw heads of commercial screwdrivers available in the market.

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The following are the aspects that must be ensured when using screwdrivers.

• Always use the correct screwdriver that is best suited for the job.
• All screw slots should be cleared of dirt/paint before applying the screwdriver head.
• Make sure the shaft is aligned with the screw during use.
• Never grind the flat blade to a chisel head.
• Ensure that a common screwdriver fills at least 75% of the screw slot.
• Always use a correct sized screwdriver, as the use of wrong sized blade may damage adjacent structures.
• Do not use the screwdrivers for chiselling or prying.
• Do not use a screwdriver to check an electric circuit as it burns the tip.
• Always rest the screwdriver on a workbench when using it on a small part.
• Extra care must be taken when using electric screwdrivers. For best usage, the screw should be started by hand and carried on using the machine.