What is the best way to measure a Stihl chainsaw bar? The best way to measure a Stihl chainsaw bar accurately is by measuring the length from the tip of the bar to the body of the saw where the chain enters, excluding the drive sprocket. You also need to know the chain pitch and gauge.
When it comes to Stihl chainsaws, having the correct information about your chainsaw bar is crucial for maintenance, purchasing replacement parts, and ensuring optimal performance. Whether you’re looking to replace a worn-out bar, buy a new chain, or simply understand your Stihl chainsaw parts better, knowing how to measure your Stihl chainsaw bar accurately is a fundamental skill. This guide will walk you through the process, covering everything from basic length measurement to deciphering other important specifications. We’ll help you with measuring Stihl bar size effectively.
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Why Accurate Measurement Matters
Why is it important to measure my Stihl chainsaw bar correctly? Measuring your Stihl chainsaw bar correctly is vital for ensuring compatibility with replacement chains, sprockets, and even other bar models if you’re considering an upgrade. Using incorrect measurements can lead to a poorly fitting chain that can damage your saw, be inefficient, or even break. This directly impacts the safety and longevity of your Stihl chainsaw.
Ensuring Compatibility for Chains and Sprockets
Your chainsaw chain and the drive sprocket on your saw are designed to work together with specific bar dimensions. A chain that is too long or too short won’t engage properly with the drive sprocket.
- Chain too short: The chain may not reach around the bar and sprocket, or it might be extremely tight, leading to rapid wear on the drive links and sprocket teeth.
- Chain too long: The chain can derail, causing damage to the bar, the saw’s clutch, and potentially leading to dangerous kickback. It also won’t cut efficiently.
Optimizing Cutting Performance
The correct Stihl chainsaw bar length influences the saw’s cutting speed and maneuverability. A bar that is too long for the saw’s engine can cause it to bog down, reducing cutting efficiency. Conversely, a bar that’s too short might not provide the reach needed for certain tasks.
Safety First
An improperly fitted chain or bar is a significant safety hazard. A derailed chain can cause serious injury. Accurate measurements ensure all components work together harmoniously, reducing the risk of unexpected malfunctions.
Key Stihl Chainsaw Bar Measurements
When you’re measuring Stihl bar size, there are a few key figures you need to know. These are not just about length; they also include the pitch and gauge of the chain that runs on the bar.
1. Stihl Chainsaw Bar Length
This is the most common measurement people refer to when discussing chainsaw bars. However, it’s important to be precise about what length you are measuring.
How to measure chainsaw guide bar length:
- The Standard Method: The industry standard for measuring chainsaw bar length is from the tip of the bar to the point where the chain first enters the bar mount (where the loop of the chain disappears into the bar’s body, connecting to the engine’s drive sprocket).
- What NOT to Include: Do not measure from the very end of the bar nose to the furthest point of the mounting bolts. You are measuring the “cutting length” or “effective length” that the chain engages with.
Measuring Stihl Bar Size – Step-by-Step:
- Place the Bar on a Flat Surface: Lay the chainsaw bar flat on a sturdy workbench or table.
- Use a Measuring Tape or Ruler: Position the end of your measuring tape or ruler at the very tip of the bar’s nose.
- Measure to the Body: Carefully extend the tape measure along the top edge of the bar until you reach the point where the chain’s drive links disappear into the bar’s mounting bracket. This is the crucial point where the chain engages with the engine’s drive sprocket.
- Read the Measurement: Note the measurement in inches or centimeters. Most chainsaw bars are measured in inches.
Common Stihl Bar Lengths: You’ll find Stihl chainsaws come with a variety of bar lengths, often ranging from 12 inches to 20 inches or even longer for professional-grade saws.
2. Chain Pitch
Chain pitch is a critical measurement that dictates the size of the drive sprocket and the spacing between the drive links on your chain. It’s the distance between any three consecutive rivets on the chain, divided by two.
What is chainsaw bar pitch? Chain pitch is a measurement of the spacing of the chain’s drive links. It’s expressed as a fraction of an inch (e.g., 3/8″, .325″, 1/4″). This measurement must match the pitch of your saw’s drive sprocket and the pitch specified for your chainsaw bar.
How to Determine Chain Pitch:
- Look at the Bar: The chain pitch is often stamped onto the base of the chainsaw bar itself, near the mounting bracket. It might be a number like “.325” or “3/8”.
- Count Drive Sprocket Teeth: A less common but sometimes necessary method is to count the number of teeth on your drive sprocket. You then find a chart online that correlates drive sprocket teeth to chain pitch.
- Measure the Chain: If the pitch isn’t stamped and you can’t determine it otherwise, you can physically measure it. Take a measuring tape and measure the distance across three rivets (which spans two full links). Divide that measurement by two. For example, if it’s 1.5 inches, the pitch is .325 inches (1.5 / 2 = 0.75, which is incorrect; it’s about 0.75″ across 3 rivets, 0.75/2 = 0.375 or 3/8). More accurately, measure from the tip of one drive link’s tooth to the tip of the next drive link’s tooth, and double that. For example, if the distance is approximately 0.75 inches, the pitch is 0.375 inches or 3/8 inch.
3. Chainsaw Bar Gauge (Drive Link Thickness)
The gauge refers to the thickness of the drive links on your chainsaw chain, which must fit snugly into the groove of your guide bar.
What is chainsaw bar gauge? Chainsaw bar gauge is the thickness of the drive links on your chainsaw chain. It’s measured in millimeters (mm) and is a crucial factor for proper chain and bar fit. Common gauges include .050″ (1.3mm), .058″ (1.5mm), and .063″ (1.6mm).
How to Determine Chain Gauge:
- Check the Bar Stamping: Like pitch, the gauge is usually stamped on the base of the guide bar, often next to the pitch. It might be shown in inches or millimeters (e.g., “.050” or “1.3mm”).
- Examine a Drive Link: You can also try to measure the thickness of a drive link with a caliper if the stamping is unreadable or missing.
4. Number of Drive Links
The number of drive links is the count of the individual pieces on your chain that engage with the drive sprocket and sit within the bar groove. This number is essential for selecting a chain of the correct length to fit your specific bar and saw combination.
How to count drive links:
- Remove the Chain: Carefully remove the chainsaw chain from the bar.
- Lay the Chain Flat: Lay the chain out in a straight line on a flat surface.
- Count the Drive Links: Count each of the “drive links” – these are the parts of the chain that have the little spurs on the bottom and fit into the bar’s groove. Start from one and count all the way around until you return to your starting point.
Why is this important? When you buy a new chain, it will be advertised with a specific length in terms of drive links (e.g., “72 drive links”). This number, along with the correct pitch and gauge, ensures the chain will fit your Stihl chainsaw bar.
Identifying Your Stihl Chainsaw Bar and Chain
Stihl is a reputable brand with a wide range of chainsaw models. To ensure you’re getting the right Stihl chainsaw parts, you need to be able to identify your bar and chain specifications.
Decoding Stihl Bar Markings
Stihl, like most manufacturers, stamps key information directly onto the chainsaw bar. Familiarize yourself with these markings to make measuring and purchasing easier.
- Length: As discussed, this is usually a number followed by “IN” or “CM”.
- Pitch: Often found as “.325” or “3/8”.
- Gauge: Frequently seen as “.050”, “.058”, or “.063”.
Example Stamping: You might see something like “1688” (which is not a standard measurement but an example of a model number) followed by “16” (for 16 inches) and then “.325 .050”. This tells you the bar is 16 inches long, with a .325 inch pitch and a .050 inch gauge.
Stihl Chainsaw Specifications
Beyond the bar itself, knowing your Stihl chainsaw model number is incredibly helpful. You can often find this on a sticker on the chainsaw housing, usually near the starter cord or on the powerhead itself.
How to use Stihl Chainsaw Specifications:
- Consult Your Owner’s Manual: Your Stihl owner’s manual is the best resource. It will list the recommended bar lengths, chain pitches, and gauges for your specific chainsaw model.
- Stihl Website: Visit the official Stihl website. You can usually enter your chainsaw model number to find detailed specifications, including compatible bar and chain sizes.
- Dealer Support: If you’re still unsure, visit your local authorized Stihl dealer. They can help you identify your saw and recommend the correct Stihl chainsaw parts.
Tools for Accurate Measurement
To get precise chainsaw bar measurements, having the right tools is essential.
Essential Measuring Tools
- Metal Ruler or Measuring Tape: A sturdy metal ruler or a good quality measuring tape is your primary tool. Ensure it has clear markings in inches and millimeters.
- Caliper (Optional but Recommended): A digital or dial caliper is invaluable for accurately measuring the chain gauge if the stamping is unclear.
- Magnifying Glass (Optional): For reading small, stamped numbers on the bar.
Tips for Using Your Tools
- Clean the Bar: Before measuring, wipe down the chainsaw bar to remove any dirt or debris that might obscure markings or affect your measurements.
- Ensure a Straight Line: When measuring length, try to keep the tape measure perfectly straight along the top edge of the bar.
- Repeat Measurements: For critical measurements, take them a couple of times to ensure consistency.
Common Pitfalls to Avoid
Even with the right tools, some common mistakes can lead to inaccurate measurements.
What not to do when measuring a chainsaw bar?
- Measuring the Wrong Length: As mentioned, don’t measure from bolt hole to bolt hole. Always use the cutting edge length.
- Guessing Pitch or Gauge: Never guess. If the markings are unclear, find a way to accurately determine them. Using the wrong pitch or gauge is a recipe for disaster.
- Ignoring Drive Link Count: A chain with the correct pitch and gauge but the wrong number of drive links will not fit your bar.
- Confusing Bar Size with Chain Size: Remember that pitch and gauge refer to the chain, which dictates the specifications of the bar it fits.
- Not Checking the Drive Sprocket: While you measure the bar, the pitch must also match the drive sprocket on your chainsaw.
Frequently Asked Questions (FAQ)
Can I use a longer or shorter bar than what’s recommended for my Stihl chainsaw?
While it’s technically possible, it’s generally not recommended. Using a longer bar than specified can overwork the engine, reduce cutting speed, and potentially damage the clutch and crankshaft. Using a shorter bar might limit your cutting capacity. Always refer to your Stihl chainsaw specifications for the optimal bar length.
How do I know if my Stihl chainsaw bar needs replacing?
Signs that your Stihl chainsaw bar needs replacing include:
* Worn Groove: If the groove where the chain sits has widened significantly, it’s time for a new bar.
* Warping: If the bar appears bent or twisted, it’s unsafe and needs replacement.
* Excessive Wear on the Nose: A worn-out roller nose can reduce cutting efficiency and increase friction.
* Cracked or Damaged Bar: Any visible cracks or damage mean immediate replacement.
What does “reduced kickback bar” mean for Stihl chainsaws?
A reduced kickback bar is designed with a smaller radius at the tip to lower the risk of dangerous kickback. While they improve safety, they can sometimes slightly reduce cutting speed. Stihl offers various bar types, including those designed for enhanced safety.
Where can I find a Stihl bar identification chart?
You can find Stihl bar identification charts on the official Stihl website, in your owner’s manual, or through reputable chainsaw parts suppliers online. These charts often correlate chainsaw model numbers with recommended bar lengths, pitches, and gauges.
Is it okay to swap parts from a different brand of chainsaw onto my Stihl?
While some universal components might exist, it’s best practice to use Stihl chainsaw parts specifically designed for your model. Using parts from other brands can lead to fitment issues, reduced performance, and potentially damage your saw. Stick with genuine Stihl chainsaw parts or high-quality compatible alternatives.
By following these guidelines, you can confidently measure your Stihl chainsaw bar and ensure you select the correct replacement parts, keeping your saw running efficiently and safely.