Why won’t a new chainsaw chain fit into the groove of a chainsaw bar?
Bought a new Husqvarna chainsaw chain and it won’t fit into the guide bar groove?
In most cases, the chain is either the wrong gauge for the guide bar, or the guide bar is worn or damaged.
This guide explains the most common causes, how to identify the problem and how to find the correct replacement chain.
Quick answer
If your new chainsaw chain won’t fit into the guide bar groove, the most common causes are:
- The chain gauge does not match the guide bar groove
- The wrong chain was purchased for the chainsaw
- The guide bar rails are worn or damaged
- The chain specifications do not match the bar and sprocket
Before installing a new chain, always check that the gauge, pitch and drive link count match the specification of your chainsaw.
What does chain gauge mean?
The gauge is the thickness of the of the chain’s drive links—the part of the chain that sits inside the guide bar groove.
For the chain to fit correctly:
- The chain gauge must match the guide bar groove width
- A chain that is too thick will not fit into the groove
- A chain that is too thin may fit loosely and operate unsafely
Common chain gauges include:
- .043" (1.1 mm)
- .050" (1.3 mm)
- .058" (1.5 mm)
- .063" (1.6 mm)
Even a small difference in gauge can prevent the chain from fitting correctly.
Does the chain gauge match the guide bar?
This is the most common reason a new chain will not fit.
Look for the chain specifications:
- On the guide bar
- On the chain packaging
- In the operator’s manual
If the gauge listed on the chain does not match the guide bar specification, the chain will not fit into the guide bar groove and should be replaced with the correct one.
Are you using the correct chain?
Many users assume that bar length is the only measurement that matters.
However, a replacement chain must match:
- Bar length
- Chain gauge
- Chain pitch
- Number of drive links
Two chains with the same bar length can still be completely different.
Example:
A 16 inch guide bar may use different chain specifications depending on the chainsaw model.
Always match the full chain specification, not just the guide bar length.
For help identifying the correct chain for your chainsaw, see the Bars & Chain Guide.
Is the guide bar worn or damaged?
If the new chain specifications are correct but the chain still will not fit, the guide bar may be worn.
Over time:
- Guide bar rails can become damaged
- The groove can become distorted
- The old chain may have worn together with the guide bar
In this situation, the original chain may appear to fit while a new chain does not.
Signs of a worn guide bar
Inspect the guide bar for:
- Bent rails
- Uneven wear
- Burrs along the edges
- A groove that appears pinched or damaged
If you notice any of these issues, replacing the guide bar may be necessary.
Is the chain installed correctly?
If the chain fits the guide bar but you are having trouble assembling it, make sure the chain is being installed correctly.
Follow the step-by-step guide:
How to assemble a chainsaw bar and chain
How to find the correct replacement chain
The easiest way to find the right chain is to check the information stamped on the guide bar.
You will typically find:
- Bar length
- Chain pitch
- Chain gauge
- Drive link information
If the markings are difficult to read, consult your operator’s manual or use the Husqvarna Bars & Chain Guide
Common mistakes to avoid
Avoid these common installation errors:
- Choosing a chain based only on guide bar length
- Ignoring chain gauge specifications
- Mixing different chain pitches
- Reusing a damaged guide bar with a new chain
- Forcing the chain into the guide bar groove
Forcing an incorrect chain can damage both the chain and guide bar.
When should you replace the guide bar?
Consider replacing the guide bar if:
- A correctly sized chain will not fit
- The guide bar rails are visibly damaged
- The groove is excessively worn
- The chainsaw frequently throws chains
A new chain and worn guide bar often do not work well together.