Garbage Disposal Allen Wrench — Size, Location, and Use
The garbage disposal Allen wrench size is 1/4 inch (6mm). This is universal across InSinkErator, Waste King, Moen, and every other major brand. The hex hole is on the bottom center of the unit, facing the floor under your sink.
If you are reading this while standing in your kitchen with a jammed disposal, that is everything you need to get started. Grab a 1/4-inch Allen wrench from a tool set, crawl under the sink, and follow the steps below.
For a full overview of disposal problems, see our garbage disposal troubleshooting guide.
Quick answer
The standard garbage disposal Allen wrench size is 1/4 inch, and this size is universal across InSinkErator, Waste King, Moen, and all other major brands. InSinkErator, which holds approximately 70% of the US residential disposal market, includes a silver “Jam-Buster” wrench with their units. The hex hole is on the bottom center of the disposal, facing the floor.
Any 1/4-inch hex key works — L-shaped, T-handle, or ball-end. You do not need a proprietary tool.
Which Wrench Do You Need?
You have several options:
The InSinkErator Jam-Buster wrench. This is a silver, crank-shaped wrench approximately 4 inches long. It ships with InSinkErator disposals and is often taped to the side of the unit or inside the product box. If you still have it, use it — the crank shape gives better leverage than a standard Allen wrench. Check the cabinet walls near the disposal; many installers tape it right there.
Any 1/4-inch Allen wrench. A standard hex key from a hardware store or from an Allen wrench set in your toolbox works identically. L-shaped keys are fine. T-handle versions give slightly better grip.
Cost. A single 1/4-inch Allen wrench runs $3-$8 at any hardware store. A full Allen wrench set costs $8-$15 and covers sizes you will need for furniture assembly, bikes, and other household tasks. The InSinkErator Badger 5, the most popular budget disposal in the US, comes with one included.
Do not buy a specialty “garbage disposal wrench” marketed at $15+ — it is the same 1/4-inch hex key in fancier packaging.
Where Is the Hex Hole?
The hex hole is on the bottom center of the disposal unit, facing the floor under the sink.
How to find it:
- Look under the sink at the disposal body
- Find the bottom plate — it faces straight down
- Look for a small hexagonal opening in the center of that bottom plate
- Some units have a small arrow or label marking it
- The red reset button is nearby — if you can see the reset button, the hex hole is close to center
If you cannot find it: The hex hole can be hard to spot on older units or in tight under-sink spaces. Trace the disposal body down from the sink flange. The bottom plate is the lowest point. Wires and the power cord exit near the bottom too — the hex hole is the only hexagonal indentation.
The exception: InSinkErator Builder Series and Amana units do not have a bottom hex hole. These models use a different unjamming method — insert a wooden spoon handle through the drain opening from above and push against the turntable to rotate it. InSinkErator’s support documentation specifies: “Use wooden spoon to rotate turntable in either direction” for Builder Series models.
How to Use the Allen Wrench
- Turn off the disposal switch and unplug the unit from the outlet under the sink. If hardwired, flip the circuit breaker
- Locate the hex hole on the bottom center of the disposal
- Insert the 1/4-inch Allen wrench into the hole
- Work the wrench back and forth in both directions. Use firm force — the jam may be stubborn. InSinkErator’s procedure states: “Work back-and-forth until one full revolution completes”
- Keep going until the wrench turns freely in complete circles in both directions. This means the flywheel is cleared
- Remove the wrench
- Remove debris — shine a flashlight into the disposal from the top and use tongs or pliers to pull out whatever was causing the jam. Common culprits: bone fragments, fruit pits, broken glass, small utensils
- Press the red reset button on the bottom of the unit. Press firmly until it clicks into place. If the button will not stay in, wait 20 minutes for the overload protector to cool down and try again
- Test — turn on cold water at the faucet, then flip the disposal switch. Run it for 30 seconds to clear remaining debris
For more unjamming methods, see our full guide on how to unjam your garbage disposal. After clearing a jam, you may need to reset the disposal if the overload protector tripped.
Video guide
Video: “How to Fix a Stuck, Humming or Broken Garbage Disposal” by The Fixer 2
When the Allen Wrench Doesn’t Work
Four scenarios where the wrench fix falls short:
The wrench won’t turn at all. The jam is severe. Try applying more force from a different angle. If you have a T-handle Allen wrench, it gives better leverage than an L-shape. Some plumbers use a breaker bar on the wrench for extra torque. If it still will not budge, the impellers may be corroded in place — on older units this happens.
The wrench turns freely but the disposal still hums. This is the diagnosis that matters most. When the flywheel rotates without resistance yet the motor still buzzes and trips the overload protector, the motor windings have burned out. Community troubleshooting data is consistent: this combination means replacement, not repair. See our guide on disposals that hum but don’t work and our page on disposal repair costs for what to expect.
No hex hole on the bottom. You have a Builder Series, Amana, or ES model from InSinkErator. Use a wooden spoon handle from the top: insert it through the drain opening, press against one of the impellers, and push to rotate the turntable. Work it back and forth until it spins freely, then remove debris with tongs. InSinkErator’s official unjamming guide{:target=“_blank”} covers this method in detail.
Disposal still doesn’t work after clearing the jam. Press the red reset button. If it was tripped, the disposal should restart. If the reset does not help, check the circuit breaker at the electrical panel. See the Family Handyman disposal repair guide{:target=“_blank”} for additional troubleshooting steps.
FAQ
What size Allen wrench do I need for a garbage disposal?
The standard garbage disposal Allen wrench size is 1/4 inch (6mm). This size is universal across all major brands including InSinkErator, Waste King, and Moen. Any standard 1/4-inch hex key works — you do not need a proprietary tool. A single wrench costs $3-$8 at hardware stores.
Where is the Allen wrench hole on a garbage disposal?
The Allen wrench hole is on the bottom center of the garbage disposal unit, facing the floor under the sink. Look for a small hexagonal opening near the red reset button. The exception is InSinkErator Builder Series and Amana models, which do not have a bottom hex hole — these use a wooden spoon method from the top instead.
Can I use a regular Allen wrench on a garbage disposal?
Yes. Any standard 1/4-inch Allen wrench or hex key works on a garbage disposal, regardless of brand. L-shaped, T-handle, and ball-end variants all fit the hex hole. InSinkErator includes a proprietary “Jam-Buster” wrench with their units, but it uses the same 1/4-inch size as a standard key.
What if my disposal doesn’t have a hex hole?
InSinkErator Builder Series, Amana, and ES models do not have a bottom hex hole. For these units, insert a wooden spoon handle through the drain opening from above, press it against the turntable or impeller, and push to rotate it in either direction until it spins freely. Remove debris with tongs before restarting.