How do I get the plug of wood out of a hole saw?
The disc jammed inside the cup, four ways to get it out, and the cuts you make before drilling so it never happens again.
- Difficulty
- beginner
- Time
- 8 min
- Read
- 3 min
Short answer
Take the arbor out of the saw, then push the plug out from the back with a screwdriver through the slots, or tap it out with a dowel. If it is jammed solid, prise it through the slots with two screwdrivers working opposite sides. Cutting a relief slot with a jigsaw across the plug before you drill prevents the whole problem.
A hole saw cuts a ring and leaves the disc inside the cup. In softwood it usually falls out; in hardwood, plywood and anything damp it swells and locks in place, and the next hole cannot be started until it is gone. It is a two-minute problem that people solve badly, usually by hammering the teeth.
Step by step
- Remove the arbor first, every time.The arbor and pilot bit block the back of the cup. Unscrewing them turns an impossible job into an easy one, and it is the step almost everyone skips.
- Push from the back, do not prise from the front.The plug went in from the front and is wedged tighter that way. Driving it back out the way it came takes far less force.
- Use the slots as designed.The slots in a hole saw's wall are there for exactly this and for dust ejection. Two screwdrivers, opposite sides, even pressure.
- Cut a relief slot before drilling next time.A jigsaw cut across the middle of the area the plug will occupy — where the material is waste anyway — lets the plug collapse inwards and fall straight out.
- Withdraw the saw during the cut.Back it out every few seconds. This clears dust, cools the teeth and stops the plug being compacted into the cup by trapped waste.
Tips
- Some hole saws have a plug-ejecting spring or a slotted arbor designed to pop the disc out. If you buy new, that feature earns its keep immediately.
- In a door where you are cutting for a lock, drill from both sides to meet in the middle. It gives a cleaner hole and produces two shallow plugs instead of one deep jammed one.
- Keep the plugs from larger saws. They are useful discs for patching, packing and jigs.
If it doesn't work
Plug is tight but movable
Cause: Normal friction fit — Fix: Remove the arbor and the pilot bit, then push a screwdriver or a length of dowel down through the back of the saw and drive the plug out from behind. This is the correct method and works most of the time.
Plug will not move at all
Cause: Swollen or compressed against the cup wall — Fix: Work two flat screwdrivers into the slots on opposite sides of the saw and lever together, walking the plug out a millimetre at a time. Steady even pressure, not a single hard prise.
Plug is deep in and the slots do not reach it
Cause: Cut deeper than the slots allow for — Fix: Drill several holes through the plug from the back with a small bit, then break it up and pull the pieces out. Sacrificing the plug is nearly always the right trade.
Plug comes out but the saw is full of compacted dust
Cause: Cutting continuously without withdrawing — Fix: Clear it with a stiff brush and a screwdriver, and change technique: withdraw every few seconds so the swarf can escape through the slots.
Plug jams on every hole in a particular material
Cause: Plywood, MDF or damp timber expanding after the cut — Fix: Cut a relief slot across the plug area with a jigsaw before drilling, or drill a finger hole through the waste so you can push the plug out from the far side.
Teeth damaged from getting a plug out
Cause: Hammering on the cutting edge — Fix: Nothing recovers a damaged tooth. Replace the saw and use the arbor-out method next time — the teeth are the only part of a hole saw with any value.
Questions people ask
Why does the plug jam more in plywood?
Plywood's alternating grain expands unevenly after the cut, and the glue lines make it harder and less compressible than solid timber.
Can I stop the plug jamming by using a slower speed?
It helps, because heat and compaction both increase with speed, but the reliable answer is the relief slot and clearing the saw during the cut.
Does the same thing happen in metal?
Yes, and the metal slug is sharp and hot. Push it out from the back with a dowel and gloves, never with fingers.