Drill bit size finder
Look up fractional, metric, number, or letter sizes — then a set that includes that label.
How to pick the right label
Start with the size system your screw, tap, or hole spec calls for — fractional inch for most shop work, ANSI numbered for small tap pilots, millimeters for metric hardware. Pick the exact label from the Size label dropdown: each option shows the label plus the decimal-inch and mm columns so you can confirm the row matches what is stamped on the fastener or printed on the box. After a label is chosen the result panel shows a single Shop CTA for the kit that includes that label; without a label there is no buy button, only the lookup results.
If your label is not in the dropdown (number, letter, large fractional, or metric outside the 1/16"–1/2" range), the finder still maps to the closest common-sizes kit and labels it as a default kit so the size match is honest.
FAQ
How do I know which drill bit size I actually need?
Pick the size system your screw, tap, or hole spec calls for, then read the exact label. For fractional inch screws the size is the body diameter in fractions (e.g. 1/4"). For ANSI numbered holes, use the #1–#80 range (e.g. #7 for a 0.201" hole). For metric hardware, the size is the body diameter in millimeters (e.g. 6 mm). When in doubt, the label stamped on the fastener or printed on the box is the truth — the finder just normalizes it to the canonical row.
What's the difference between fractional, number, and letter drill bit sizes?
All three are ANSI B94.11M-1993 encodings of decimal-inch body diameters. Fractional (e.g. 1/16", 1/4") uses common fractions and is the most common shop-floor convention. Number (#1–#80) and letter (A–Z) are older wire-gauge-derived tables that fill the gaps between common fractions. All three convert exactly to mm via decimal_inch × 25.4, so the finder treats them as parallel systems rather than competing ones.
Why does the Shop button only appear after I pick a size?
A drill bit set that "includes your size" is only honest once a size is selected — so the Shop CTA is gated on a chosen label. Picking a label triggers one (and only one) Shop CTA in the result panel: "Shop set including 1/4"" (or whatever label you picked). Without a label there is no Shop button and no price, because the finder cannot tell which set would actually include the size you need. A generic "buy a drill bit set" link would not match the lookup intent of the page.
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