since they are self-drilling, bugle screws do not want pilot holes. Their special form distributes the pressure throughout a wider floor compared to flat screws.
you might acquire all the small print you would like https://franceskmkc469353.verybigblog.com/29152200/how-much-you-need-to-expect-you-ll-pay-for-a-good-types-of-screw-heads