How do you measure the bar on a chainsaw? You measure the chainsaw bar by first identifying the “cut length” and then checking the “drive link count.” This two-step process ensures you get the correct chainsaw bar size for your needs.
A chainsaw is only as effective as its weakest component, and often, the chainsaw bar is a critical factor in its performance. Whether you’re a seasoned professional or a weekend warrior tackling yard work, knowing how to accurately measure your chainsaw bar is crucial. This isn’t just about guesswork; it’s about chainsaw bar identification and ensuring you select the right chainsaw bar replacement or understand your current setup. This guide will walk you through the simple yet essential steps to determine your chainsaw bar length and other vital chainsaw bar specs.
Image Source: i.ytimg.com
Why Measuring Your Chainsaw Bar Matters
Getting the right chainsaw bar size is more than just a minor detail. It directly impacts:
- Cutting Efficiency: A bar that’s too long or too short can lead to inefficient cuts, bogging down the engine, and increased wear on your chain and bar.
- Safety: An incorrectly sized bar can cause the chainsaw to kickback more violently, posing a serious safety risk.
- Component Compatibility: Chainsaw bars are designed to work with specific chain pitches, gauges, and drive links. Mismatching these can lead to premature wear or outright failure.
- Engine Performance: The engine is designed to operate optimally within a certain range of bar lengths. A longer bar than recommended puts more strain on the engine.
Fathoming Chainsaw Bar Terminology
Before we dive into measuring, let’s clear up some key terms:
- Chainsaw Bar Length: This is the measurement from the tip of the bar to the point where it meets the chainsaw body. It’s often referred to as the “cutting length.”
- Chainsaw Bar Gauge: This is the thickness of the groove in the bar where the drive links of the chain sit. It’s usually measured in millimeters (e.g., 0.050″ or 1.3mm, 0.058″ or 1.5mm).
- Chainsaw Bar Pitch: This refers to the distance between the drive links of the chain. It’s determined by measuring the distance between three rivets on the chain and dividing by two. Common pitches are 3/8″, .325″, and .404″.
- Drive Links: These are the links on the chainsaw chain that fit into the groove of the chainsaw bar and are powered by the sprocket.
How To Measure The Bar On A Chainsaw: The Simple Method
There are two primary ways to measure your chainsaw bar: the “cut length” method and the “drive link count” method. Both are effective, but the drive link count is often considered the most precise for compatibility.
Method 1: Measuring the “Cut Length”
This is the most common and straightforward way people think of measuring a chainsaw bar.
Steps:
- Safety First: Ensure your chainsaw is turned off and the chain brake is engaged. It’s always best to remove the bar and chain from the chainsaw body for accurate measurement, but you can also do this while it’s attached if you’re careful.
- Grab a Tape Measure: You’ll need a standard tape measure.
- Measure from the Tip: Place the end of the tape measure at the very tip of the chainsaw bar.
- Measure to the Motor Casing: Extend the tape measure along the top of the bar until you reach the point where the bar meets the chainsaw’s motor housing. Crucially, do not include the portion of the bar that inserts into the saw. This is the “cutting length.”
- Record the Measurement: Write down the measurement. Chainsaw bar lengths are typically given in inches (e.g., 16 inches, 18 inches, 20 inches).
Example: If your tape measure reads 18 inches from the tip to where the bar enters the saw body, you have an 18-inch chainsaw bar.
Important Note on “Cut Length”: While this measurement is widely used and understood, it’s an approximation. Manufacturers often round up or down, and slight variations can occur. For absolute certainty, especially when ordering a chainsaw bar replacement, the drive link count is more reliable.
Method 2: Counting Drive Links (The Most Accurate Way)
This method focuses on the actual interface between your chain and bar, providing the most precise chainsaw bar specs for compatibility.
Steps:
- Safety First: Again, ensure the chainsaw is off and the chain brake is engaged.
- Remove the Chain and Bar: For the easiest and most accurate count, it’s best to remove the chain and bar from the chainsaw body.
- Identify the Drive Links: These are the small, flat pieces on the bottom of the chain that are designed to fit into the groove of the bar.
- Count the Drive Links: Starting with any drive link, count each individual drive link along the entire length of the chain. You can also do this with the chain still on the bar, but removing it makes it much easier.
- Record the Count: Note down the total number of drive links.
Connecting Drive Links to Bar Length:
Chainsaw manufacturers have a standard correlation between the number of drive links and the bar length. While the “cut length” is what we commonly refer to, the drive link count is the actual specification that ensures your chain fits your bar correctly.
Here’s a general guide:
| Drive Links | Typical Cut Length (Inches) | Common Pitch | Common Gauge |
|---|---|---|---|
| 52 | 14″ | .325″, 3/8″ | .050″, .058″ |
| 56 | 16″ | .325″, 3/8″ | .050″, .058″ |
| 60 | 18″ | .325″, 3/8″ | .050″, .058″ |
| 64 | 20″ | .325″, 3/8″ | .050″, .058″ |
| 68 | 22″ | .325″, 3/8″ | .050″, .058″ |
| 72 | 24″ | 3/8″, .404″ | .050″, .058″, .063″ |
| 76 | 26″ | 3/8″, .404″ | .050″, .058″, .063″ |
| 81 | 28″ | .404″ | .063″ |
| 84 | 30″ | .404″ | .063″ |
Why is this important? Because different chainsaw bar types might have slightly different overall lengths for the same “cut length” designation, but they will all use chains with the same number of drive links for a specific pitch and gauge.
Beyond Length: Other Crucial Chainsaw Bar Specs
When considering a chainsaw bar replacement or buying a new one, length is only part of the story. You must also know the chainsaw bar gauge and chainsaw bar pitch.
Deciphering Chainsaw Bar Pitch
The pitch is the spacing of the chain links. It dictates the size of the sprocket that drives the chain. Using the wrong pitch will prevent the chain from engaging correctly with the sprocket, leading to poor performance or damage.
- How it’s measured: Pitch is calculated by measuring the distance between three consecutive rivets on the drive link and dividing that distance by two.
- Common Pitches:
- .325″: Often found on smaller to medium-sized homeowner and occasional-use saws.
- 3/8″: Common on prosumer and professional saws. It offers a slightly faster cut than .325″.
- .404″: Typically used on larger, professional-grade saws for heavy-duty cutting.
How to identify the pitch on your current bar:
- Look for markings: Many bars have the pitch stamped on them, often near the mount or on the side.
- Measure a chain: If you have the chain off, measure between three rivets on a drive link and divide by two.
- Consult your chainsaw manual: The owner’s manual will list all the correct specifications.
Fathoming Chainsaw Bar Gauge
The gauge refers to the thickness of the drive links. This thickness needs to match the groove in the bar.
- How it’s measured: It’s measured in inches or millimeters.
- Common Gauges:
- .050″ (1.3 mm): Found on lighter-duty saws.
- .058″ (1.5 mm): Very common on a wide range of saws.
- .063″ (1.6 mm): Typically used on heavier-duty saws with larger chains.
How to identify the gauge on your current bar:
- Look for markings: The gauge is usually stamped on the bar, often near the pitch.
- Measure a drive link: Use calipers to measure the thickness of a drive link.
- Consult your chainsaw manual: The owner’s manual is your best resource.
Comprehending Chainsaw Bar Mount Type
The “mount” is the pattern of bolts and slots that attach the bar to the chainsaw body. Different manufacturers and even different models within the same manufacturer use different mount types. This is critical for chainsaw bar replacement. You cannot put a bar with the wrong mount onto your chainsaw.
- Identifying the Mount: This can be tricky as there are many variations. The best way is to:
- Check the old bar: Look for markings or identifying features.
- Consult your chainsaw manual: This will clearly state the mount type.
- Compare with online charts: Many chainsaw parts websites have charts showing different mount types with diagrams. Look for the shape of the mounting hole and the number of bolts used.
Common mount types include Husqvarna mounts (e.g., “H42”), Stihl mounts (e.g., “22”), and various others for brands like Echo, Poulan, McCulloch, and more.
Identifying Your Chainsaw Bar Specs Without Measuring
Sometimes, you might not have the bar readily available for measurement, or you want to confirm its identity before ordering. Here’s how:
1. Check Your Chainsaw’s Owner’s Manual
This is the gold standard. Your owner’s manual will provide the exact chainsaw bar specs, including:
- Recommended bar length
- Required chain pitch
- Required chain gauge
- Bar mount type
2. Look for Markings on the Existing Bar
Most chainsaw bars have the essential information stamped directly onto them.
- On the side near the mount: You’ll often find the pitch (e.g., .325, 3/8) and gauge (e.g., .050, .058) stamped here.
- On the side near the tip: Sometimes, the length (in inches) is also stamped here.
- Look for brand-specific codes: Some brands use alphanumeric codes that can be cross-referenced to identify the bar type and compatible chains.
3. Examine the Chainsaw Model Number
If you know your chainsaw’s exact model number (e.g., “Stihl MS250,” “Husqvarna 450 Rancher”), you can often find the specifications online.
- Manufacturer’s Website: Check the product page for your specific chainsaw model.
- Chainsaw Parts Retailers: Reputable online stores that sell chainsaw parts will have detailed product listings that include bar specifications for various models.
4. Count the Drive Links (Again!)
As mentioned earlier, if you have the chain, counting the drive links is a foolproof way to determine your bar’s intended size, especially when paired with the chain’s pitch and gauge.
Common Mistakes to Avoid When Measuring
- Measuring the Wrong Length: Forgetting to exclude the part of the bar that goes into the saw.
- Incorrectly Identifying Pitch or Gauge: Assuming you know the pitch and gauge without double-checking the markings or consulting your manual.
- Ignoring the Mount Type: Buying a bar that physically won’t attach to your chainsaw.
- Using a Worn-Out Bar for Measurement: A heavily worn bar with a widened groove can give a misleading measurement for chain fit.
Frequently Asked Questions (FAQ)
Q1: Can I use a longer or shorter bar than what my chainsaw came with?
A: While sometimes possible, it’s generally not recommended without consulting your chainsaw’s manual or a professional. A longer bar puts more strain on the engine and can affect balance and safety. A shorter bar might not perform as efficiently for certain tasks. Always check your manual for the recommended bar length range.
Q2: What happens if my chain pitch or gauge doesn’t match my bar?
A: If the pitch is wrong, the chain won’t engage with the drive sprocket, and the saw won’t cut. If the gauge is wrong, the drive links won’t fit snugly in the bar groove. A drive link that’s too thin will cause the chain to sit too low, leading to premature wear on the drive sprocket and bar. A drive link that’s too thick won’t fit into the groove at all.
Q3: How do I know which chainsaw bar type to buy?
A: You need to know your chainsaw’s brand, model number, and the specific bar mount type. Matching the bar mount is the most critical step for physical compatibility. Then, ensure the new bar has the correct pitch, gauge, and a compatible cutting length for your saw.
Q4: Do I need to replace the chain when I replace the bar?
A: It’s highly recommended. Chains and bars wear together. If your bar is worn out, your chain likely is too. Installing a new bar with an old, worn chain will cause both components to wear out much faster. Always use a new chain with a new bar for optimal performance and longevity.
Q5: Where can I find a list of chainsaw bar types and their corresponding mount codes?
A: You can find comprehensive lists on specialized chainsaw parts websites or forums. Many retailers provide cross-reference guides based on chainsaw make and model. Your owner’s manual is also the best source for your specific saw’s requirements.
By following these simple steps, you can confidently measure your chainsaw bar and ensure you have the correct specifications for any replacement or maintenance needs. This knowledge is key to keeping your chainsaw running safely and efficiently for years to come.