Symptoms
- Bolt caps reveal corroded, discolored bolts underneath
- Wrench slips or bolt won't turn at all
- Nut is fused to the bolt with rust
- Trying to remove the toilet for wax ring replacement or other work
Likely causes
- CommonLong-term moisture exposureBathroom humidity and occasional water contact corrode base bolts over years.
- PossibleLow-quality or non-corrosion-resistant hardwareCheaper steel bolts rust faster than brass or stainless versions.
- PossibleBolts never removed since original installationBolts left untouched for many years are more likely to have corroded solidly onto the threads.
What to do
- Apply a penetrating oil to the nut and let it soak for 15–30 minutes.
- Try turning the nut with a properly fitted wrench or socket, using steady pressure rather than jerking, which can snap the bolt.
- If it still won't budge, try a nut splitter tool, which cracks the nut off without needing to turn it.
- As a last resort, cut the bolt with a hacksaw blade or an oscillating multi-tool, working carefully to avoid damaging the porcelain.
- Replace old bolts with new brass or stainless toilet bolts when you reinstall or reset the toilet.
Tools and parts
- Penetrating oil
- Wrench or socket set
- Hacksaw blade or oscillating tool
- Nut splitter (optional)
Brass toilet bowl boltsSearch: “brass toilet floor bolts kit”
When to call a pro
Call a plumber if the bolts won't budge safely, especially if you need the toilet removed for another repair like a wax ring.
Safety
Use caution
Work carefully with a saw blade near porcelain to avoid chipping or cracking the toilet base.