.325 Saw Chain Sizes (Sizing Guide)
A .325-inch chain is not a complete size. Match its pitch to the saw’s sprocket and bar nose, its gauge to the bar groove, and its drive-link count to the exact bar and saw model. Check the markings and owner’s manual before buying. Bar length alone cannot tell you which chain will fit.
When comparing replacement chains, the .325-inch label can look like a clear answer. It is only one measurement. A chain can have the correct pitch and still be wrong for your bar because its gauge or drive-link count does not match.
I use the same check every time: identify the saw and bar, read the chain markings, then confirm all three chain dimensions against the manual or bar maker’s information. This small step can prevent a costly mistake and helps you avoid relying on a listing that says only “fits a .325 saw.”
What .325-inch chain size means
Pitch describes the spacing of a chain’s rivets. Gauge describes the thickness of its drive links, and drive-link count tells you how many links run around the bar. All three must match the saw and bar. The .325-inch pitch is 8.25 mm, but it does not identify a complete chain size.
Pitch: the first compatibility check
Pitch is measured by taking the distance between the centers of three consecutive rivets and dividing it by two. For .325-inch chain, that measurement is .325 inches, or 8.25 mm.
The chain pitch must match both the drive sprocket on the saw and the sprocket at the bar nose. A chain with a different pitch is not a safe substitute, even if it appears close in size. Check the saw and bar information rather than guessing from the chain’s appearance.
Gauge: match the bar groove
Gauge is the thickness of the chain’s drive links, which sit inside the bar groove. Common .325-inch chain gauges include .043, .050, .058, and .063 inches. Not every gauge is available or approved for every chain, bar, or saw.
The chain gauge must match the bar groove exactly. If it is too thin or too thick, the chain may not ride properly. A mismatch can contribute to poor control or chain derailment. Do not force the chain onto the bar to see if it fits.
Drive links: count them
Drive links are the downward-facing parts of the chain that travel inside the bar groove and engage with the saw’s drive sprocket. Count these links when checking size. The drive-link count is often marked on a chain package or listed in the bar or saw maker’s fit information.
Bar length does not establish drive-link count. Two bars with the same stated length can require different chain counts due to differences in their design. Use the count specified for your exact bar and saw combination.
How to find the correct chain size
The most reliable way to choose a chain is to identify the saw and bar, then verify pitch, gauge, and drive-link count in the manuals or maker’s fit data. Chain or bar markings can help, but do not rely on a single marking if the parts may have been changed.
Follow this sizing sequence
- Identify the saw. Record the make, model, and any relevant model variant from the saw’s label. Find the operator’s manual or official parts information.
- Identify the bar. Look for markings on the bar, such as its part number, pitch, gauge, or chain-link count. If the markings are worn or absent, use the bar’s part number to check the maker’s specifications.
- Read the chain information. Check the package or chain markings for pitch, gauge, and drive-link count.
- Compare all three. Confirm that the chain matches the saw’s drive sprocket, the bar’s nose sprocket and groove, and the required link count.
- Confirm approved setup. Use only bar lengths and chain types approved for the exact saw model.
A shop or product listing may describe chain size in a short format that combines pitch, gauge, and link count. The order and style can vary, so read the labels rather than assuming every brand uses the same format.
Size-check table
| Check | What to match | What it tells you |
|---|---|---|
| Pitch | Chain, saw drive sprocket, and bar nose sprocket | Whether the chain’s rivet spacing fits the sprockets |
| Gauge | Chain drive-link thickness and bar groove | Whether the chain sits properly in the bar |
| Drive-link count | Chain and exact bar specification | Whether the chain length fits the bar and saw |
| Bar length | Approved length for the saw model | Whether the bar is an allowed setup |
| Chain type | Chain type approved for the saw and bar | Whether the chain is appropriate for that equipment |
Sizing scenarios: what to do before ordering
The examples below are checks, not model-specific fit claims. They show how to resolve common shopping situations without guessing.
| Situation | What you know | Next step |
|---|---|---|
| The saw manual lists .325-inch pitch, but the bar gauge is unknown | Pitch alone | Find the bar part number or gauge marking before buying |
| A replacement chain matches pitch and gauge, but link count is different | Two of three chain dimensions | Do not install it; verify the required count for the exact bar |
| A listing says “fits 18-inch bar” | Bar length only | Ask for pitch, gauge, and drive-link count, then check against your setup |
| The chain repeatedly loosens or climbs from the bar | Fit or condition may be wrong | Stop; check chain size, tension, bar, and sprocket before reuse |
Equipment Setup and Safety Preparation
Safe setup starts before installation. Work with the engine off and cool, and use the manual for the saw’s specific steps. Check that the chain, bar, and sprocket fit together, and inspect safety parts before starting. If any dimension or part condition is uncertain, resolve it before operating the saw.
Inspect and install the chain
Wear a helmet with face and eye protection, hearing protection, chainsaw chaps, gloves, and protective boots. Clear the work area and plan an escape path before starting. Check the bar groove, oil port, sprocket, chain brake, and chain catcher for damage or blockage.
With the engine off and cool, engage the chain brake and fit the correct chain into the bar groove. On the top of the bar, the cutters must face forward, toward the bar nose. Follow the saw manual to tension the chain. With gloves on, check that it seats correctly and moves by hand as directed by the manual.
Do not operate a loose, damaged, or poorly lubricated chain. If the chain climbs, binds, or repeatedly loosens, stop and check pitch, gauge, link count, tension, bar, and sprocket. A gauge mismatch can make the chain ride incorrectly and contribute to derailment. Inspect the parts before using the saw again.
Field Cutting Operation
Once the chain is fitted, check the saw’s operating instructions before cutting. Starting steps, bar-oil needs, fuel mix, idle speed, and maximum engine speed vary by model. None can be determined from .325-inch pitch or engine size alone, so use the operator’s manual.
Start the saw using the maker’s procedure, with the saw secured and chain brake engaged as directed. Confirm that the chain receives oil and that the chain brake works as described in the manual before cutting. Keep a firm two-handed grip, avoid contact with the guide-bar nose, and do not cut above shoulder height.
After the first running period, stop and check chain tension as directed by the manual. Let the saw cool before making adjustments. Recheck tension after initial use and cooling, since a chain can change tension as it warms.
Chain Maintenance, Sharpening, and Saw Tuning
Maintenance keeps a correctly sized chain in working condition. Sharpening and depth-gauge settings depend on the chain type and its maker’s instructions. There is no single depth-gauge clearance that applies to every .325-inch chain, so do not use a general setting in place of the chain’s specification.
A depth gauge, also called a raker, controls how deeply a cutter enters the wood. If it is set incorrectly, the chain may cut poorly or increase kickback risk. Use the chain maker’s instructions and the correct tools for that chain type. Also check for damaged cutters, worn drive links, and changes in tension.
Use the saw manual for fuel mix, idle and wide-open-throttle RPM, bar-oil requirements, and approved bar length. These are model-specific settings, not properties of .325-inch chain. If the saw’s performance changes, check the chain and lubrication first, then follow the maker’s diagnostic steps rather than changing engine settings by guesswork.
Storage and Seasonal Care
Before storing the saw, engage the chain brake, stop the engine, and let the equipment cool. Clean the bar groove and oil port, inspect the chain for wear or damage, and check its tension. Follow the saw maker’s storage instructions, and keep the chain covered when the saw is stored.
Keep chain and bar information with the saw’s records or take clear photos of the markings. That makes the next replacement easier to verify. If you change a bar or sprocket, check compatibility again; the old chain’s size may not fit the new parts.
A practical buying checklist
Before you place an order, confirm each item below. If a listing leaves out a measurement, contact the seller or check the part maker’s official information instead of filling in the gap from bar length alone.
- Saw make and exact model identified
- Bar part number or exact bar specification identified
- .325-inch pitch confirmed for the chain, drive sprocket, and bar nose
- Chain gauge matches the bar groove
- Drive-link count matches the exact bar and model
- Bar length and chain type are approved for the saw
- Chain maker’s sharpening and depth-gauge instructions are available
A chain that passes all these checks is a better match than one selected by pitch alone. If any specification conflicts, pause the purchase and verify the parts.
Frequently Asked Questions
These answers cover the checks that most often cause confusion when choosing .325-inch chain. For any saw-specific value, the operator’s manual and the exact bar specification take priority over a general guide or retailer listing.
Is .325-inch chain the same as 8.25 mm pitch?
Yes. .325 inches converts to about 8.25 mm. The pitch describes the distance between rivets, measured as half the distance across three consecutive rivet centers. You must still match gauge and drive-link count.
Can I choose a .325 chain by bar length alone?
No. Bar length does not tell you the required drive-link count or gauge. Check the exact bar and saw specifications before buying.
What gauges are available for .325 chain?
Common gauges include .043, .050, .058, and .063 inches. Availability varies by chain and bar. Match the chain’s drive-link thickness to the bar groove exactly.
Can I use a .325 chain on any .325 saw?
No. The pitch must match, but the gauge and drive-link count must also fit the bar and saw. Use only approved bar lengths and chain types for the exact model.
How do I find the drive-link count?
Check the chain package or chain markings, and confirm the count against the bar or saw maker’s fit information. Count the drive links if markings are missing, then verify the result against the exact bar specification.
What happens if the chain gauge is wrong?
The chain may not sit correctly in the bar groove. That can lead to poor operation or chain derailment. Do not force a mismatched chain onto the bar.
Is there one correct raker setting for all .325 chains?
No. Set depth-gauge clearance to the chain manufacturer’s specification for that chain type. An incorrect setting can cause poor cutting or increase kickback risk.
Why does a correctly sized chain keep loosening?
Stop the saw and check tension, wear, and the fit of the chain, bar, and sprocket. Repeated loosening can signal a problem that needs correction before the saw is used again.
Can .325-inch pitch tell me the right fuel mix or bar oil?
No. Fuel mix, bar-oil requirements, and engine settings depend on the saw model. Follow the operator’s manual.
What should I do if my bar markings are worn off?
Look for the bar part number and verify its specifications through the bar maker or saw maker. Do not choose a chain based only on the saw’s stated pitch or bar length.
(This article was written by one of our staff writers, Marcus Thorne. Visit our Meet the Team page.)
