What are Phillips head and Roberts head classified as?

Phillips head and Roberts head are classified as screw head types because they are specific designs of the heads of screws that accommodate different types of screwdrivers. The Phillips head features a cross-shaped (or "+" shaped) indentation, designed to grip the screwdriver more effectively and allow for higher torque without stripping the screw. This design is intended to provide better control when fastening or removing screws.

The Roberts head, on the other hand, also features a similar cross design but with unique characteristics that differentiate it from the Phillips head, making it more suited for certain applications, like when dealing with softer materials.

Understanding these classifications is important for identifying the appropriate tools needed for various fastening tasks in firefighting and construction, where secure fittings of equipment are critical for safety and efficiency.