What is a drill bushing?
In this guide
A drill bushing is a hardened sleeve, set in a jig, that guides a drill bit to an exact spot and keeps it straight. Carr Lane, a maker of jig parts, calls them precision guides for drills, reamers, taps and counterbores.
This guide is part of our drilling hub. For the bits that pass through bushings, see types of drill bits.
What a drill bushing does
A drill bit wants to wander when it starts, and it can lean as it goes deeper. A bushing stops both. The bit runs inside a hard, tight sleeve, so:
- The hole goes in the right spot, every time.
- The hole runs straight (or at the jig's set angle).
- Each part drilled in the jig matches the last one.
The bushing is harder than the bit's sides, so the bit doesn't wear it fast. Carr Lane's standard bushings are 1144 steel hardened to Rockwell C 62 to 64 on the inside. For very long runs, there are carbide bushings.
Uses
- Production jigs in machine shops. A plate with bushings sits over the part. The machinist drills every hole without measuring.
- Dowel jigs. The steel guides you drill through are bushings. Milescraft's dowel jig uses swappable bushings held in a retaining plate.
- Pocket-hole jigs. Kreg calls the drill guide block the heart of its jig. Its hardened steel guides hold the bit at the pocket angle.
- Portable drill guides. Kreg's portable drill guide has six hardened steel guides from 1/8 to 1/2 inch, for straight holes with a hand drill.
- Reaming and tapping. A bushing can guide a reamer or a tap, so the finished hole lines up with the drilled one.
Types of drill bushings
Carr Lane sorts standard drill bushings into three groups: permanent, renewable and air-feed. In the US, the inch sizes and codes come from the ASME B94.33 standard for jig bushings.
| Type (Carr Lane code) | What it is | Use it when |
|---|---|---|
| Press-fit, headless (P) | A plain sleeve pressed into the jig plate | Short runs; the bushing stays for good |
| Press-fit, head type (H) | Same, with a collar (head) on top | You want the head to sit on the plate or in a counterbore |
| Liner (L, HL) | A permanent sleeve that holds renewable bushings | Long runs, or soft jig plates |
| Slip/fixed renewable (SF) | A bushing that drops into a liner and locks with a screw | You'll swap it when it wears, or change sizes |
| Air-feed | A shank-and-collar system | Self-feeding air drills in production |
Carbide versions add a "C" to the code (PC, HC, SFC).
Slip vs fixed renewable
A fixed renewable bushing stays in its liner until it wears out. A slip renewable bushing is made for fast changes. You can drill with one, then slip in a reamer bushing of a different size in the same liner. Carr Lane says slip/fixed renewable bushings are the most common type.
Sizing rules machinists use
Carr Lane gives these rules of thumb:
| Rule | Value |
|---|---|
| Bushing length (bearing length) | About 1 1/2 times the tool diameter |
| Gap from bushing to part, drilling | 1/2 to 1 1/2 times the tool diameter |
| Gap from bushing to part, reaming | 1/4 to 1/2 times the tool diameter |
| Jig plate thickness | About 1 to 2 times the tool diameter |
The gap under the bushing lets chips escape. Too small, and chips pack in and wear the bushing. Too big, and the bit can drift before it reaches the part.
Drill bushing vs similar parts
| Part | What it does | Not the same because |
|---|---|---|
| Drill bushing | Guides a bit into a hole | — |
| Router template bushing | Rides a template edge to steer a router | Guides sideways travel, not a plunging bit |
| Sleeve bearing (bronze bushing) | Lets a shaft spin in a housing | Supports a turning shaft; doesn't guide a cutter |
| Center punch | Dents the spot so the bit starts there | Only helps the start; doesn't hold the bit straight |
How to choose one
For home use, you rarely buy a loose bushing. You buy a jig that has them.
- For dowels, get a dowel jig with bushings in the sizes you use. Common sets are 1/4, 5/16 and 3/8 inch.
- For pocket screws, a pocket-hole jig has the bushing built in.
- For straight holes without a drill press, use a portable drill guide. It's a good help when you drill into metal or need a clean hole at an angle.
- For a shop jig, pick the type from the table above, and match the inside size to your bit. Our drill bit size chart lists fraction, number and letter sizes.
Bushings work with any bit that fits, but a sharp bit matters more than the guide. For hard metal, see the best drill bit for hardened steel. Our drill bit selector matches the bit to the material.
Key takeaways
- A drill bushing is a hard sleeve that guides a drill bit. It sets where the hole goes and keeps the bit straight.
- Standard bushings are hardened steel, about Rockwell C 62 to 64 inside, per Carr Lane. Carbide is used for long runs.
- Main types: press-fit (permanent), renewable (swap when worn) and liners (hold the renewable ones). ASME B94.33 sets the inch sizes.
- Shop rule of thumb: the bit should ride in the bushing for about 1 1/2 times its diameter, with a chip gap of 1/2 to 1 1/2 diameters below.
- At home, the hardened guides in dowel jigs, pocket-hole jigs and drill guides are drill bushings.
Questions people ask
What is the purpose of a drill bushing?
It guides the drill bit. The bushing puts the hole in the right place, keeps the bit from wandering at the start, and holds it straight. That makes every part drilled in the jig match.
What is the difference between a drill bushing and a liner?
A liner is a bushing pressed into the jig plate to hold a renewable bushing. The renewable bushing guides the bit and gets swapped when it wears or when you need a different size. The liner stays put.
What is a slip renewable bushing?
It's a renewable bushing made to be changed quickly. You can drill with one size, then slip in another size, like a reamer bushing, in the same liner. Carr Lane groups slip and fixed renewable bushings as type SF.
What are drill bushings made of?
Most are hardened steel. Carr Lane's standard bushings are 1144 steel hardened to Rockwell C 62 to 64 inside. Carbide, tool steel, stainless and bronze are also used.
Is a drill bushing the same as a router bushing?
No. A router template bushing, or guide bushing, rides along the edge of a template to steer a router. A drill bushing guides a drill bit straight down into a hole.
Sources
- Carr Lane Manufacturing: Understanding standard drill bushing types
- ASME B94.33: Jig bushings (ANSI webstore listing)
- Kreg: How to use a pocket-hole jig (hardened steel drill guides)
- Kreg Portable Drill Guide KDG-6000: six hardened steel guides, 1/8 to 1/2 in
- Milescraft dowel jig instructions: bushings and retaining plate
Change log: Nov 6, 2026: Rewritten from the 2023 archive post. Cut repeated sections; added Carr Lane type codes, hardness and length rules, ASME B94.33, and the DIY jigs where readers actually meet bushings.
