Question

1. which screwdriver is self - centering and is now considered the most commonly used?

phillips
offset
torx
pozidriv

Explanation:

Phillips screwdrivers are self - centering. They have a cross - shaped tip. Over time, due to their design which allows for better engagement and less slippage compared to some other types (like flat - head), they have become very common. The Pozidriv is similar but with more flutes, Torx has a star - shaped pattern, and Offset is a different design (angled).

Answer:

Phillips