What size drill bit for a Tapcon?
Pick your Tapcon screw size and get the exact carbide drill bit — it's one size under the screw. A ¼" Tapcon takes a 3/16" bit, not a ¼" bit.
Tapcon screw size
Nominal Tapcon diameter — 3/16" through ¾". 3/16" and ¼" are the common DIY sizes.
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How Tapcon sizing works
The one thing that trips people up: the drill bit is one size under the screw, never the same. A ¼" Tapcon takes a 3/16" bit, not a ¼" bit; a 3/16" Tapcon takes a 5/32" bit. That’s deliberate — a Tapcon cuts its own threads into the masonry, so the hole has to leave solid material for those hardened threads to bite into. Match the hole to the screw and there’s nothing to grip.
Drill deeper than the screw will sit — ¼" deeper for 3/16" and ¼" screws, 1" deeper for 3/8" and up — so the dust the bit makes has somewhere to go and the screw seats fully. Keep at least 1" of embedment in solid base material.
You need a hammer drill and a carbide bit
This is masonry, a different tool class than the rest of the site’s wood work. Tapcons go into solid concrete, brick or block, which means a hammer drill (or rotary hammer) set to hammer + rotation, plus a carbide-tipped bit meeting ANSI B212.15 in the size above. A regular twist bit in a regular drill will not make a usable hole. Drill into the brick itself, not the mortar joint, for the best hold. For structural, heavy, or code-governed work, follow the anchor manufacturer’s published data and your local code.
Common questions
What size drill bit for a 1/4 Tapcon?
A 1/4" Tapcon uses a 3/16" carbide bit — not a 1/4" bit. The bit is deliberately one size under the screw so the Tapcon's threads cut into the concrete and grip. Drill the hole at least 1/4" deeper than the screw will sit (to clear the dust), with a minimum 1" embedment, using a hammer drill and a carbide-tipped masonry bit.
Do you need a special drill bit for Tapcons?
Yes. Tapcons go into concrete, brick or block, so you need a carbide-tipped masonry bit (the ones meeting ANSI B212.15, the size printed on the Tapcon box) driven by a hammer drill or rotary hammer. A regular twist bit in a regular drill won't cut a usable hole in masonry. Many Tapcon packs include the correctly sized bit — a 3/16" bit for 3/16" screws, 3/16" for 1/4" screws, and so on.
Why is the Tapcon bit smaller than the screw?
Because a Tapcon cuts its own threads into the masonry. If the hole matched the screw diameter there would be nothing for the threads to bite into. Making the hole one size under (a 1/4" screw into a 3/16" hole) leaves solid material for the hardened threads to tap into, which is what gives the anchor its hold. It trips people up, but the undersized hole is correct.
Can you use a regular drill for Tapcons?
Not reliably. Drilling into solid concrete, brick or block needs the percussive action of a hammer drill (or rotary hammer) set to hammer-plus-rotation, together with a carbide-tipped bit. A standard drill and a standard bit will struggle to make the hole, overheat the bit, and won't give a clean hole for the anchor to grip. Masonry is a different tool class than wood work.
Full Tapcon drill-bit chart
Download PDFTapcon drill bit size chart
| Tapcon screw | Carbide drill bit | Hole depth |
|---|---|---|
| 3/16"common DIY size | 5/32"4 mm | ¼" past the screw |
| 1/4"common DIY size | 3/16"4.8 mm | ¼" past the screw |
| 3/8" | 5/16"7.9 mm | 1" past the screw |
| 1/2" | 7/16"11.1 mm | 1" past the screw |
| 5/8" | 1/2"12.7 mm | 1" past the screw |
| 3/4" | 5/8"15.9 mm | 1" past the screw |
The bit is always smaller than the screw — that’s correct; the threads cut into the masonry for grip. Hole depth: drill at least ¼" deeper than the screw for 3/16" and ¼" Tapcons, 1" deeper for 3/8" and up, to clear the dust; minimum embedment 1".
Requires a hammer drill (hammer + rotation) and a carbide-tipped bit meeting ANSI B212.15. Works in solid concrete, brick and block — drill into the brick itself, not the mortar joint, for the best hold.
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Where these numbers come from
The bit-for-each-Tapcon sizes are cross-referenced across five-plus sources including the official Tapcon installation instructions, which agree exactly: the carbide bit is one size under the screw. These are the standard-convention starting points — always check the size printed on your Tapcon packaging, which is the authoritative spec for that product. This page covers Tapcon-style concrete screws only; wedge, sleeve and drop-in anchors size differently and get their own pages.
These are standard-convention Tapcon sizes for typical DIY light-to-medium concrete, brick and block work. Always follow the bit size printed on the anchor packaging. For structural, heavy, or code-governed work, follow the anchor manufacturer's published data and your local building code.