What's the Difference Between Self-Drilling and Self ...
2020-7-15u2002·u2002The most important difference between self-tapping and self-drilling screws is that self-tapping screws cannot go through metal without a pilot hole, which must be pre-drilled or pre-punched. Exact drill or punch hole size is also important. The screw will become loose and not thread properly and securely if the hole's too big.
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