See a letter "A" on your drill bit? You're holding the first and smallest size in the letter-gauge drilling system. Perhaps unsurprisingly, this standardized series runs alphabetically from A to Z. On ...

Gear-obsessed editors choose every product we review. We may earn commission if you buy from a link. Why Trust Us? The Takeaway: Diablo’s Impact Strong Step Drill Bits are a fast, convenient way to ...