Which screwdriver size is indicated by a letter T followed by a number, such as T10?

The designation of a screwdriver size indicated by a letter T followed by a number, such as T10, refers specifically to a Torx screwdriver. Torx screwdrivers are characterized by their star-shaped bit, which allows for better grip and torque when driving screws. This design helps prevent stripping the screw head and provides a more secure engagement than many other types of screwdrivers.

Torx screws are commonly found in automotive, electronics, and appliance applications due to their effectiveness in ensuring that screws remain tight. The number following the letter T indicates the size of the Torx bit; for example, T10 is a specific size within the Torx system.

Other types of screwdrivers, such as precision, hex, or flathead screwdrivers, do not use this specific naming convention, making it clear that the correct answer is indeed relating to Torx screwdrivers.