What's inside
As an Amazon Associate I earn from qualifying purchases. This post may contain affiliate links at no extra cost to you.
Removing the slug—the round metal plug left inside an annular cutter—should take seconds, but forcing it out can damage the cutter, the drill, or your hands. The safest method depends on whether the slug is loose, stuck in the cutter, hot, or distorted by drilling conditions. Stop the machine, disconnect its power, and let the workpiece and cutter cool before handling either part.
What the Slug Is and Why It Sticks
An annular cutter removes material around the edge of the hole instead of grinding out the entire center. The remaining disk is the slug. Cutting fluid and the cutter’s pilot pin normally push it out at the end of the cut.
A slug can stay lodged when the cutter exits only partway, the pilot pin is short or damaged, chips pack inside the cutter, or the workpiece moves during drilling. Heat can also expand the slug enough to clamp it inside the cutter. A crooked cut may leave a wedge-shaped slug that cannot slide straight out.
Do not try to remove it while the cutter is spinning. Never hold the slug with your fingers near the teeth, even if the drill is switched off but still connected to power. Carbide and high-speed-steel teeth are sharp enough to cut skin with little pressure.
The Safe Removal Process
1. Shut down and inspect
Release the feed pressure, switch off the drill, unplug it or remove its battery, and wait for all movement to stop. If the cutter was used on thick steel, allow several minutes for cooling. Hot cutting fluid can cause burns, and a hot slug may remain above 200°F even when it looks harmless.
Wear safety glasses and cut-resistant gloves for handling the workpiece, but do not rely on gloves to protect against rotating machinery. Secure the drill and workpiece so neither can tip while you work.
2. Check the pilot pin
With the cutter facing downward, press the pilot pin inward using a wood dowel, brass punch, or other soft-metal tool. A properly functioning pin should move smoothly and push the slug out. Avoid a hardened steel punch against the cutter’s bore; a missed blow can chip teeth or bell-mouth the cutter.
For a small, loose slug, gravity and a gentle push are usually enough. If the slug does not move, do not escalate immediately to a hammer. First clear packed chips from the cutter using a brush. Compressed air can propel sharp chips into your eyes, so use eye protection and keep the air pressure moderate.
3. Use controlled tapping only if needed
Place the cutter on a wood block with the teeth supported without bearing directly on them. Tap the pilot pin with a small brass or plastic-faced hammer. Use light blows—roughly the force needed to seat a small nail, not a framing hammer swing. Rotate the cutter between taps if the slug is cocked.
If the slug moves a few millimeters and stops, inspect for a burr or a chip wedged between the slug and cutter wall. Pull the slug with pliers only after enough of it is exposed to grip securely. Locking pliers can crush a thin slug and make it tighter, so standard pliers are often the better choice.
4. Deal with a seriously stuck slug
For a slug that is wedged near the cutter’s teeth, remove the cutter from the machine if possible and place it in a vise with soft jaws. Do not clamp directly across the teeth. Push from the pilot-pin end with a brass drift or a hardwood dowel. If the slug will not move, stop and identify the cause rather than applying more force.
A penetrating oil may help with a cold, rusted slug, but it will not fix a slug distorted by excessive feed pressure. Keep oil away from hot metal and electrical parts, and wipe the cutter clean before drilling again. Never heat the cutter with a torch. Heat can draw the temper from high-speed steel, damage carbide brazing, and create a fire hazard from cutting fluid.
Slug Removal Methods Compared
| Method | Best use | Main risk | My verdict |
|---|---|---|---|
| Push the pilot pin by hand | Loose slug after a complete cut | Minimal; avoid sharp teeth | First choice |
| Brush out chips, then push | Chip-packed cutter | Flying chips if blown carelessly | Usually enough |
| Light brass or plastic tapping | Slug stuck but not distorted | Damage from excessive impact | Good second step |
| Pliers on the exposed slug | Slug protruding from the cutter | Crushing or bending the slug | Useful with a firm grip |
| Heat, prying, or heavy hammering | Almost never justified | Ruined cutter, burns, broken teeth | Avoid |
Tools Worth Buying for the Job
A basic brass punch set is the most useful addition for regular annular-cutter work. Brass is softer than the cutter and less likely to raise a burr inside the bore. A plastic-faced hammer, small bench vise with soft jaws, nylon brush, and safety glasses complete a practical removal kit.
If you drill often, a replacement annular cutter pilot pin set is worthwhile. A bent, shortened, or mushroomed pin is a common reason slugs fail to eject. Match the pin to the cutter’s diameter, length, and arbor system; generic-looking pins are not automatically interchangeable.
For occasional drilling, you do not need an expensive slug-ejection system. A sound pilot pin and a brass punch are usually sufficient. Spend more on a better cutter only when you are drilling thick plate, stainless steel, or many holes per day, where tooth durability and consistent ejection matter.
Preventing the Next Stuck Slug
Use the cutter at the manufacturer’s recommended speed and feed. Pushing too lightly can rub and overheat the teeth; pushing too hard can distort the slug and overload the arbor. Apply cutting fluid suited to the material, especially in steel. Keep the cutter perpendicular to the workpiece and clamp loose stock firmly.
When drilling thick material, periodically ease off the feed to clear chips, but do not repeatedly lift the cutter so far that it loses the pilot hole. Make sure the cutter fully exits the workpiece before stopping the feed. Afterward, inspect the teeth for chips, the pilot pin for free movement, and the cutter bore for packed metal.
If the slug is badly wedged, the cutter teeth are damaged, or the arbor has begun to wobble, replacing the cutter is cheaper than repairing a damaged drill or creating an unsafe setup. A cutting fluid for annular cutters and a nylon parts cleaning brush set cost little compared with a ruined cutter, and both help prevent the problem.