18 Inch Drill Bit for Concrete Block: Drill All the Way Through in One Pass
The Problem
Some jobs need a hole through the full length of a concrete block. A standard bit runs out of reach halfway down, and you're stuck. An 18 inch drill bit for concrete block fixes that. You drill from the top, push straight through, and come out the other side in one pass.
Bad Dog's Extra Long 18" Multipurpose Set is built for exactly that job. This post covers how it works, what's in the set, and why it's more than a masonry bit with extra length.
Why a Standard Bit Can't Drill Through Concrete Block
A regular-length bit only goes so deep. When you need to drill the long way through a block, from top to bottom, you run out of bit before you run out of block. Stopping partway means a blind hole, not a through-hole.
Long bits solve the reach problem, but many aren't built to handle masonry. Bad Dog's 18" bit keeps the same construction as our regular multipurpose bit. It's the same bit with more length.
How the 18" Bit Drills Through Block, Top to Bottom
Set the bit on top of the block and drill straight down. The 18" length lets you cut the full distance without stopping or switching bits.
You'll know it's working when powder comes out of the hole in the center of the block. That's concrete being cut and cleared as the bit goes through.
TO GET THE BEST RESULTS
- Chuck the bit and start drilling at the top of the block.
- Keep the bit spinning at speed. Bad Dog bits need at least 2,500 RPM. The cutting angle is less aggressive than a traditional drill bit, so low speed makes it look like the bit isn't working.
- Let the bit do the cutting and keep drilling straight through.
- Watch for the powder coming out of the center hole as the bit advances.
What's in the 18" Four-Piece Set
The set comes in four sizes:
| Size | Length | Shank |
|---|---|---|
| 1/4" | 18" | Hex |
| 3/8" | 18" | Hex |
| 1/2" | 18" | Hex |
| 3/4" | 18" | Round with flat |
The 1/4", 3/8" and 1/2" bits have quick-connect hex shanks. The 3/4" bit has a heavy-duty round shank with a flat side for a secure grip.
Same Bad Dog Bit, More Reach
The 18" bit is built like our regular multipurpose bit. It has the same carbide, titanium and cobalt tip. Regular masonry bits don't use that combination. Most use carbide alone. Our tip is made to be tougher than plain carbide and to hold an edge the way a cobalt bit does.
The tip is brazed to an armored steel shank. The shank is built to flex rather than snap off in the hole.
That tip does more than concrete block. It also drills steel, wood, tile, plastic and stone, so one long bit handles whatever's in the way. All of it is made in Bristol, Rhode Island, and we've been making drill bits since 1988.
Ready to Go Deeper?
Extra Long 18" 4 pc Multipurpose Set
Made in USA. Lifetime guaranteed: if it dulls or breaks, we repair or replace it.
Questions? Call 800-252-1330
FAQ
Can you drill all the way through a concrete block with an 18 inch bit?
Yes. The 18" length lets you drill the full distance of the block, top to bottom, in one pass. In our video, powder comes out of the hole in the center of the block as the bit cuts through.
What sizes come in the 18" set?
Four sizes: 1/4", 3/8", 1/2" and 3/4". The first three have hex shanks and the 3/4" has a round shank with a flat side.
Is the 18" bit the same as your regular multipurpose bit?
Yes, apart from the length. It has the same carbide-titanium-cobalt tip and the same construction. It's just extra long.
What RPM do I need?
At least 2,500 RPM. The tip has a less aggressive cutting angle than a traditional bit, so slow speeds make it look like the bit isn't working. If you're unsure, run it at full speed.
What else can the 18" bit drill?
Besides concrete block, it drills steel, wood, tile, plastic and stone.
Written by Joseph Strong on 22nd Oct 2026 I’m JJ Strong, a mechanical engineer and third-generation tool designer at Bad Dog Tools, our American-made, family-run company built on durability and innovation. I grew up hauling booths and talking tools at trade shows before I could even drive. Now I design and build and improve our next generation of lifetime-guaranteed tools - our custom induction brazing system to our precision sharpening technology. On weekends, you’ll find me restoring my ’86 Land Rover Defender or ’54 Jaguar XK120 and seeing just how much I can build (or break) with Bad Dog Tools.