How To Measure Chainsaw Chain Length Correctly: Simple Guide

Can you measure a chainsaw chain without removing it? While it’s challenging to get a perfectly accurate measurement without disassembling the chain, you can often estimate it or verify its size using specific methods. However, for the most precise measurements, removing the chain is recommended.

A chainsaw is only as good as its chain. A sharp, correctly sized chain makes cutting easier, faster, and safer. But what happens when your chain starts to dull, break, or you need to replace it? You’ll need to know your chainsaw chain size. This guide will walk you through how to measure chainsaw chain length accurately, ensuring you get the right replacement part every time.

How To Measure Chainsaw Chain Length
Image Source: www.parkerbrand.co.uk

Why Knowing Your Chainsaw Chain Size Matters

Using the wrong size chain can be more than just an inconvenience. It can lead to:

Poor Cutting Performance: A chain that’s too loose will skip and bounce. A chain that’s too tight will bind and strain your saw.
Increased Wear and Tear: An ill-fitting chain can damage your chainsaw’s bar, sprocket, and even the engine due to increased friction and stress.
Safety Hazards: A loose chain can fly off the bar, posing a serious risk of injury. A chain that’s too tight can cause overheating and potential component failure.
Voiding Warranties: Using incorrect parts can sometimes void your manufacturer’s warranty.

Key Measurements for Chainsaw Chains

To correctly measure chainsaw chain, you need to know three primary measurements: chainsaw chain pitch, chainsaw chain gauge, and the chainsaw chain count (or loop length). These three factors determine compatibility with your chainsaw and bar.

1. Chainsaw Chain Pitch

What is chainsaw chain pitch? Pitch is the distance between the drive links of a chainsaw chain. It’s measured from the center of the first rivet to the center of the third rivet, then divided by two. In simpler terms, it’s the spacing of the chain.

Common pitches include:

.325 inches
3/8 inch (also known as 0.375 inches)
.404 inches
1/4 inch (less common on standard chainsaws, often found on smaller carving saws)

How to Measure Pitch:

The Quick Method (Visual Inspection): Look for numbers stamped directly onto the chain’s drive links or the chain brake. These numbers often indicate the pitch. For example, you might see “325” for .325 pitch or “375” for 3/8 pitch. Sometimes, it’s printed on the chainsaw bar itself, usually near the base where it attaches to the saw.
The Measurement Method:
1. Take your chainsaw chain and lay it flat.
2. Count the number of drive links along a specific section. Drive links are the parts of the chain that sit inside the bar groove.
3. Measure the distance from the center of the first drive link’s rivet to the center of the twelfth drive link’s rivet. This measurement should be exactly 6 chain pitches.
4. Divide this total measurement by 6. The result is your chain’s pitch.
5. For example, if the distance from the center of the first rivet to the center of the twelfth rivet is 6 inches, then your pitch is 1 inch (6 inches / 6 pitches = 1 inch per pitch). If the measurement is 4.875 inches, then your pitch is .325 inches (4.875 inches / 6 pitches = 0.8125 inches per pitch, which is not standard. This highlights the need for accuracy. A more common measurement for .325 would be around 4.875 inches for 12 drive links, or 3.9 inches for 10 drive links).
6. Another common method is to count the rivets on a specific length of the chain. For example, count the rivets on a 24-inch section of chain. If you have 24 drive links, the distance between rivets is typically 1 inch, meaning a pitch of .325.

Tools for Measuring Pitch:

While a ruler can work for the measurement method, specialized tools offer more precision. Some manufacturers offer a chainsaw chain measuring tool that has notches or guides to help align the rivets for accurate pitch identification.

2. Chainsaw Chain Gauge

What is chainsaw chain gauge? Gauge refers to the thickness of the drive link, which is the part of the chain that fits into the groove of the guide bar. A thicker gauge provides more strength and durability, while a thinner gauge can offer better flexibility and reduce weight.

Common gauges include:

.050 inches (or 1.3mm)
.058 inches (or 1.5mm)
.063 inches (or 1.6mm)

How to Measure Gauge:

Visual Inspection: Like pitch, the gauge is often stamped on the chain itself, usually on the drive links. You might see “050,” “058,” or “063.” It’s also frequently printed on the guide bar.
The Measurement Method:
1. Carefully remove a drive link from the chain. This might require a chain breaker tool.
2. Use a caliper or a ruler with fine markings to measure the thickness of the drive link. Measure across the widest part of the drive link’s base, where it would sit in the bar groove.
3. Ensure you’re measuring the actual metal thickness, not any part of the connecting rivet.

Tools for Measuring Gauge:

Digital Caliper: This is the most accurate tool for measuring gauge. It provides precise measurements in inches or millimeters.
Ruler with Millimeter Markings: If a caliper isn’t available, a ruler with millimeter markings can be used, but it requires a steady hand and careful observation.

3. Chainsaw Chain Count (Loop Length)

What is chainsaw chain count? This refers to the total number of drive links in the chainsaw chain loop. This number is crucial because it directly determines the length of the chain and, therefore, the length of the guide bar your chainsaw can accommodate. Chainsaw bars are usually advertised by their cutting length, but the number of drive links is the definitive measure for chain compatibility.

How to Measure Chain Count:

Visual Inspection: Again, check for markings on the chain or bar. Sometimes, the number of drive links is indicated.
The Counting Method:
1. Lay the chain flat on a surface.
2. Start with a drive link and count each drive link until you complete the entire loop.
3. Make sure you count every single drive link.

Important Considerations for Chain Count:

Bar Length vs. Drive Links: A common misconception is that you measure the bar’s length. While bar length is important for overall saw performance, the drive link count is what you need for chain compatibility. For example, a 20-inch bar doesn’t mean the chain is 20 inches long. The chain will have a specific number of drive links that corresponds to that bar length.
Consistency: Manufacturers aim for consistency. If you have a 20-inch bar, your chain will likely have a specific drive link count that’s standard for that pitch and gauge combination.

How to Identify Chainsaw Chain: Putting It All Together

To correctly identify chainsaw chain, you need all three key measurements: pitch, gauge, and drive link count. Often, you can find this information directly from your chainsaw’s manual or the stamped numbers on the existing chain or guide bar.

Example Chain Identification:

Let’s say you find the following information:

Pitch: Stamped “325” on the drive link.
Gauge: Stamped “058” on the drive link.
Drive Link Count: You counted 72 drive links.

This means your chainsaw chain is a .325 pitch, .058 gauge chain with 72 drive links. This is the complete chainsaw chain size you need to look for when purchasing a replacement.

Practical Steps for Measuring Your Chainsaw Chain

Here’s a step-by-step guide to help you measure chainsaw chain accurately:

Step 1: Safety First!

Always ensure your chainsaw is off and the spark plug wire is disconnected before you begin handling the chain. This prevents accidental starting.

Step 2: Locate Existing Markings

Check the Chain: Inspect the drive links. Look for numbers that might indicate pitch (e.g., 325, 375, 404) and gauge (e.g., 050, 058, 063).
Check the Guide Bar: Many guide bars have the pitch and gauge stamped on them, usually near the connection point to the chainsaw body. This is often the easiest place to find the critical measurements.
Check the Chainsaw Manual: Your owner’s manual is a treasure trove of information about your specific saw, including the correct chain specifications.

Step 3: Measure Pitch (If Markings Are Unclear)

Lay the chain flat.
Place a ruler at the center of a rivet on a drive link.
Count 12 drive links.
Measure the distance from the center of the first rivet to the center of the twelfth rivet.
Divide this measurement by 6. This gives you the pitch in inches.

Step 4: Measure Gauge (If Markings Are Unclear)

If possible, use a chain breaker tool to remove one drive link.
Use a digital caliper to measure the thickness of the base of the drive link.
If you don’t have a caliper, use a ruler with millimeter markings, but be as precise as possible.

Step 5: Count Drive Links

Lay the chain out in a loop.
Start at one drive link and count each drive link consecutively until you complete the full circle.

Using a Chainsaw Chain Measuring Tool

A dedicated chainsaw chain measuring tool can simplify the process, especially for pitch. These tools often have guides or slots that help you align the rivets precisely.

How to Use a Measuring Tool:

Lay the tool flat.
Position a section of your chain onto the tool, aligning the rivets with the tool’s markings.
The tool will have indicators for pitch and gauge.
You will still need to count the drive links separately.

What If You Can’t Find the Information?

If you’ve exhausted all avenues and still can’t find the correct chainsaw chain size, here are a few more options:

Take the Old Chain to a Dealer: The most reliable method is to take your old chain to an authorized chainsaw dealer. They have the expertise and tools to accurately measure and identify your chain, and they can help you find the correct replacement.
Take the Bar to a Dealer: If your chain is too damaged to measure, but the bar is intact, take the bar to a dealer. The pitch and gauge are stamped on the bar, and they can use the bar to help you find the correct chain, even if you don’t know the drive link count (they can usually infer it).

Common Mistakes to Avoid

Measuring the Bar Length Instead of Drive Links: Remember, bar length is a guideline, but drive link count is the precise measurement for chain compatibility.
Incorrectly Measuring Pitch: Measuring from the tip of one tooth to the tip of another tooth, or from the outside of one drive link to the outside of another, will give you an inaccurate pitch. Always measure from rivet center to rivet center.
Confusing 3/8″ Pitch with 3/8″ LP (Low Profile): While both are 3/8 inch pitch, they have different drive link thicknesses and are not interchangeable. Always check the gauge.
Not Considering Gauge: Even if the pitch and drive link count match, an incorrect gauge can cause problems.
Assuming All Chains for a Bar Length Are the Same: While there’s a standard drive link count for a given bar length and pitch, different manufacturers might use slightly different specifications. Always verify.

Table: Chainsaw Chain Measurement Summary

Measurement	What It Is	Common Values	How to Measure
Pitch	Distance between drive links (center rivet to center rivet)	.325″, 3/8″, .404″	Measure 12 drive links, divide by 6. Or check stamped numbers on chain/bar.
Gauge	Thickness of the drive link that fits into the bar groove	.050″, .058″, .063″	Measure drive link thickness with calipers. Or check stamped numbers on chain/bar.
Drive Links	Total number of drive links in the chainsaw chain loop	Varies widely (e.g., 56, 64, 72, 84)	Count each drive link in the chain loop. Or check stamped numbers on chain/bar.

Maintaining Your Chainsaw Chain

Properly maintaining your chain will extend its life and ensure it performs optimally.

Sharpening: Keep your chain sharp using a file or a grinding tool. A dull chain requires more force, leading to premature wear.
Tensioning: Regularly check and adjust chain tension. A chain that’s too loose can derail, while one that’s too tight causes excess friction and wear. The chain should be snug but still movable by hand.
Lubrication: Ensure your saw’s automatic oiler is functioning correctly. Proper lubrication reduces friction and heat, preventing premature wear and seizing.
Cleaning: Keep your chain clean, especially after use in muddy or dirty conditions. Remove debris that can accumulate in the drive links and cutters.

Frequently Asked Questions (FAQ)

Q1: How do I know what pitch and gauge my chainsaw needs?
A1: The easiest way is to check the stamping on your current chain or on the guide bar. If those are unreadable, consult your chainsaw’s owner’s manual.

Q2: Can I use a chain with a different pitch or gauge than what’s recommended?
A2: No. Using an incorrect pitch or gauge can damage your saw and bar, and it’s a significant safety risk.

Q3: If my bar says “20-inch bar,” does that mean my chain is 20 inches long?
A3: No, the “20-inch” refers to the cutting length of the bar. The chain’s length is determined by the number of drive links, which is specific to that bar size and pitch.

Q4: I lost my owner’s manual. How can I find the chain size?
A4: Check the chainsaw itself. The pitch and gauge are almost always stamped on the guide bar. If not, take your old chain or bar to a reputable dealer for identification.

Q5: What does “3/8” on a chain mean?
A5: It refers to the pitch, meaning the distance between drive links is 3/8ths of an inch. It’s important to also know the gauge (thickness) as there’s also a “3/8 Low Profile” (3/8 LP) which is thinner and not interchangeable with standard 3/8.

By diligently following these steps and paying attention to the key measurements, you can confidently measure chainsaw chain and ensure your saw is always equipped with the correct chainsaw chain size for optimal performance and safety. A well-maintained and correctly fitted chain is the backbone of efficient and safe chainsaw operation.