Self-tapping screws are Self-Drilling screws but there are differences between a self-tapping screw and a self-drilling screw
Self-tapping screws – these screw`s functions are mainly based on their threads. They cut their threads themselves and remove the material completely from the device or sheet when a hole is drilled. They can be used for hard wood and strong metals.
Self-drilling screws – these screws mainly suit soft metals and devices. They drill their holes themselves without the need for a pilot hole.
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