What is the easiest way to measure a chainsaw bar? The simplest way to measure a chainsaw bar is to count the number of drive links on the chain. This is because chainsaw bar length is directly related to the number of drive links and the pitch and gauge of the chain.
So, you need to replace your chainsaw bar, but you’re not sure how to measure it correctly. Don’t worry, this guide will walk you through every step of measuring chainsaw bar length, deciphering chainsaw bar numbers, and even identifying your chainsaw bar models. We’ll cover everything from the basics of chainsaw bar nomenclature to practical tips for getting an accurate chainsaw bar measurement.
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Why Measuring Your Chainsaw Bar Matters
Getting the right chainsaw bar length is crucial for your saw’s performance and safety. An incorrectly sized bar can lead to:
- Poor Cutting Performance: Too short, and you won’t be able to make the cuts you need. Too long, and your saw will struggle, overheat, and cut inefficiently.
- Increased Wear and Tear: An improper fit can cause undue stress on the chain, sprocket, and even the engine, leading to premature wear.
- Safety Hazards: A bar that’s too long can cause the saw to kickback more violently. A bar that’s too short might not be able to handle the power of your saw, leading to unexpected behavior.
- Chain Fit Issues: Chains are designed for specific bar lengths, pitches, and gauges. Using the wrong bar means your chain won’t fit correctly, making it impossible to use your chainsaw safely.
This detailed chainsaw bar measurement guide will ensure you get it right every time.
Fathoming Chainsaw Bar Nomenclature
Chainsaw bars have a specific way they are identified, and this chainsaw bar nomenclature is key to finding replacements. You’ll often see numbers and letters stamped onto the bar itself. These are not random; they tell you important chainsaw bar specifications.
- Pitch: This is the distance between the drive links on your chain. It’s measured from the center of one rivet to the center of the next, then divided by two. Common pitches include .325″, 3/8″, and .404″.
- Gauge: This refers to the thickness of the drive link that fits into the bar groove. Common gauges are .050″ and .063″.
- Drive Links: These are the teeth on the bottom of the chain that engage with the sprocket and sit inside the bar groove.
Knowing these aspects of your chainsaw chain length and how they relate to the bar is fundamental.
Determining Chainsaw Bar Size: The Easiest Method
The most straightforward way to determine your chainsaw bar size involves looking at the chainsaw bar numbers stamped on the bar itself. However, if these numbers are worn or illegible, counting drive links is the most reliable fallback.
Method 1: Reading the Numbers on the Bar
Most chainsaw bars have a model number or code stamped onto them, usually near the base where the bar meets the saw body. This code often contains information about the bar’s length, pitch, and gauge.
Where to Look:
- Top or Bottom of the Bar Mount: The mounting end of the bar (the part that attaches to the chainsaw) is the most common location for stamps.
- Near the Tip: Sometimes, smaller numbers might be found closer to the tip of the bar.
What the Numbers Mean (General Interpretation):
While specific chainsaw bar identification varies greatly between manufacturers and even different chainsaw bar models, you can often decipher some key information:
- Length: The number often corresponds directly to the cutting length in inches (e.g., “18” for an 18-inch bar).
- Pitch: This might be indicated by a number like “325” (for .325″) or “375” (for 3/8″).
- Gauge: Similarly, “050” (for .050″) or “063” (for .063″) might appear.
Example: A stamp like “20-325-050″ could mean an 20-inch bar with a .325″ pitch and a .050” gauge.
Important Note: This is a general interpretation. Always consult your chainsaw’s owner’s manual or the manufacturer’s website for precise chainsaw bar specifications related to their specific numbering system.
Method 2: Counting Drive Links (The Foolproof Way)
If the numbers on your bar are unreadable, or you want to be absolutely sure, counting the drive links on your chain is the most accurate way to determine chainsaw bar length.
What You Need:
- Your chainsaw with the chain mounted.
- A marker or crayon.
- A quiet, well-lit area.
Steps to Count Drive Links:
- Remove the Chain (Optional but Recommended): While you can count with the chain on the saw, removing it makes it much easier to get an accurate count and avoid mistakes.
- Lay the Chain Flat: Spread the chain out on a flat surface, making sure it’s not tangled.
- Identify a Starting Point: Pick a single drive link to start your count. You can mark it with a piece of chalk or a crayon so you don’t lose your place.
- Count Each Drive Link: Carefully count every drive link in the chain. A drive link is the part of the chain that has the two small metal tabs extending downwards, designed to fit into the bar groove and engage the sprocket.
- Stop at Your Starting Point: Continue counting until you reach your marked starting link. Do NOT count the starting link again. The total number you arrive at is the number of drive links.
Common Drive Link Counts and Corresponding Bar Lengths:
The number of drive links is directly correlated to the chainsaw bar size for a given pitch and gauge. While there can be slight variations between manufacturers and specific chainsaw bar models, here’s a general guideline:
| Drive Links | Common Bar Length (inches) |
|---|---|
| 56 | 14 |
| 60 | 16 |
| 64 | 18 |
| 68 | 20 |
| 72 | 22 |
| 76 | 24 |
Example: If you count 64 drive links on your chain, you likely have a bar that is approximately 18 inches long. This is a crucial piece of information for measuring chainsaw bar effectively.
Method 3: Measuring the Bar Directly (Less Precise but Useful)
While not as exact as counting drive links, measuring the bar itself can give you a rough idea, especially if you’re trying to visually confirm a size.
What You Need:
- A measuring tape or ruler.
Steps for Direct Measurement:
- Identify the Cutting Length: The “bar length” of a chainsaw typically refers to the cutting length, which is the length of the part of the bar that extends beyond the nose sprocket.
- Measure from the Sprocket to the Tip: Place the end of your measuring tape at the point where the chain’s drive links engage the nose sprocket. Extend the tape to the very tip of the bar.
- Record the Measurement: Note down the measurement in inches.
Important Caveat: This measurement is not the same as the drive link count correlation. A bar that measures 18 inches from the sprocket to the tip will likely have a chain with 64 drive links. This method is more of a visual confirmation of the nominal length.
Additional Factors for Chainsaw Bar Identification
Beyond length, other chainsaw bar specifications are critical for ensuring compatibility and proper function.
Pitch and Gauge: The Silent Partners
As mentioned earlier, pitch and gauge are vital.
- Pitch: This determines how the chain’s drive links fit into the bar’s groove and engage the drive sprocket. Using the wrong pitch will prevent the chain from fitting or cause it to derail.
- Gauge: This refers to the thickness of the drive link. The bar groove must match the chain’s gauge precisely. Too tight, and the chain won’t move freely; too loose, and it can fall out or wear excessively.
How to Find Pitch and Gauge:
- On the Bar: Often, pitch and gauge are stamped near the length number on the bar itself. Look for numbers like “325” or “3/8” for pitch, and “050” or “063” for gauge.
- On the Chain: The pitch and gauge are usually stamped on the drive links of the chain itself.
- Owner’s Manual: This is the best source for definitive chainsaw bar specifications.
Number of Drive Links for Your Specific Saw
Once you know your pitch and gauge, you can use a chart or your owner’s manual to find the correct number of drive links for a given bar length. Conversely, if you count drive links, knowing the pitch and gauge helps you confirm the bar’s nominal length.
Matching a New Bar to Your Chainsaw
Once you’ve determined your current bar’s specifications, you can confidently select a replacement.
Compatibility Checks:
- Mount Type: Chainsaw bars have different mounting types to fit specific chainsaw chainsaw bar models and brands. Examine the mounting end of your current bar and compare it to potential replacements. Your owner’s manual will specify the correct mount type for your saw.
- Engine Size and Power: While not directly a bar measurement, your chainsaw’s engine size dictates the maximum recommended bar length. Using a bar that’s too long for your saw’s power will strain the engine, leading to overheating and reduced performance. Check your owner’s manual for recommended bar lengths for your specific chainsaw model.
- Brand and Model: Always prioritize bars made for your specific chainsaw brand and model. While some aftermarket bars might fit, using OEM (Original Equipment Manufacturer) parts or reputable aftermarket brands designed for your saw is always best.
Buying Guide:
- Owner’s Manual: This is your ultimate resource. It will list the correct bar length, pitch, gauge, and mount type for your chainsaw.
- Manufacturer’s Website: Most manufacturers have online parts lookup tools where you can enter your chainsaw model number and find compatible parts.
- Reputable Chainsaw Supply Stores: Staff at these stores are knowledgeable and can help you find the right bar if you provide your chainsaw model and current bar details.
Troubleshooting Common Chainsaw Bar Issues
Sometimes, things don’t go as planned. Here are a few common issues and how to address them.
Worn or Illegible Numbers
As covered, if the numbers are gone, count your drive links. This is the most reliable way to ensure you get the correct chainsaw chain length and consequently, the right bar.
Chain Derailment
If your chain keeps coming off the bar:
- Incorrect Pitch/Gauge: This is the most common cause. Ensure your chain’s pitch and gauge match the bar and sprocket.
- Loose Chain: The chain tension might be too low. Adjust it according to your owner’s manual.
- Worn Sprocket: A worn sprocket can cause the chain to slip.
- Damaged Bar Groove: If the groove in the bar is bent or damaged, it won’t hold the chain properly.
Inefficient Cutting
If your saw is cutting poorly:
- Dull Chain: Chains need regular sharpening.
- Incorrect Chain Tension: A chain that’s too tight or too loose will perform poorly.
- Wrong Bar Length: If the bar is too long for the saw’s power, it will struggle.
- Bar Rail Wear: The rails of the bar can wear down, affecting chain contact.
Frequently Asked Questions (FAQ)
Q: Can I use a longer bar on my chainsaw?
A: While you might be able to physically fit a longer bar, it is generally not recommended unless your chainsaw owner’s manual specifically allows for it. Using a bar that is too long for your saw’s engine can lead to overheating, reduced power, premature wear on the engine and drive components, and increased risk of kickback. Always refer to your owner’s manual for recommended bar lengths.
Q: What does the number stamped on my chainsaw bar mean?
A: The numbers stamped on a chainsaw bar typically indicate its specifications. The most common numbers represent the bar’s length (in inches), the chain’s pitch (e.g., .325″, 3/8″), and the chain’s gauge (e.g., .050″, .063″). However, the exact meaning can vary between manufacturers and specific chainsaw bar models. Always consult your owner’s manual for precise interpretation of chainsaw bar identification for your saw.
Q: How do I know what pitch and gauge my chainsaw chain is?
A: The pitch and gauge of your chainsaw chain are usually stamped directly onto the drive links of the chain. Look for numbers like “325” or “375” for pitch, and “050” or “063” for gauge. If the numbers on the chain are worn, you can also find this information in your chainsaw’s owner’s manual or by measuring the distance between drive links (for pitch) and looking up common specifications.
Q: Is it okay to mix and match brands for bars and chains?
A: It is best to use chains and bars that are designed to work together, ideally from the same manufacturer. However, as long as the pitch, gauge, and number of drive links are compatible, you can often use chains from one reputable brand on bars from another. Always double-check chainsaw bar specifications and chain compatibility before mixing brands to avoid poor performance or damage.
Q: How often should I replace my chainsaw bar?
A: A chainsaw bar should be replaced when the rails become worn, damaged, or distorted. You can often prolong the life of a bar by flipping it over periodically to ensure even wear. Signs that your bar needs replacement include: the bar groove being widened or uneven, the rails being burred or bent, or if you notice a significant decrease in cutting performance even with a sharp chain. Many professional users inspect their bars regularly and replace them after a certain number of chain sharpenings or hours of use, depending on their cutting conditions.
By following this comprehensive chainsaw bar measurement guide, you can confidently identify and select the correct chainsaw bar size for your needs, ensuring your chainsaw operates safely and efficiently. Whether you are reading chainsaw bar numbers or counting drive links, accuracy is key to maintaining your equipment and achieving the best cutting results.