What is the correct way to measure a Stihl chainsaw bar length? The correct way to measure a Stihl chainsaw bar length is by measuring from the tip of the bar nose to the mounting point where it attaches to the chainsaw body, not including the drive sprocket.
Knowing your Stihl chainsaw bar length is crucial for several reasons. It ensures you purchase the correct replacement chain, sprocket, and potentially even a different length bar if you wish to modify your saw’s capabilities. Using the wrong size components can lead to poor performance, premature wear, and even damage to your chainsaw. This guide will walk you through the straightforward process of Stihl chainsaw bar measurement, ensuring you get it right every time.
Why Accurately Measuring Your Stihl Chainsaw Bar Matters
Your chainsaw’s bar length dictates the maximum size of wood you can cut in a single pass. It also influences the type of chain your saw uses, specifically its chainsaw chain pitch and gauge. The pitch refers to the distance between drive links, and the gauge is the thickness of the drive links. These are critical specifications that must match your bar and saw.
Crucial Components of Chainsaw Bar Measurement
- Bar Length: The primary measurement we’re concerned with.
- Pitch: The spacing of the chain’s drive links.
- Gauge: The thickness of the drive links.
- Number of Drive Links: The total count of drive links on the chain that engage with the sprocket and sit within the bar groove.
Simple Steps for Measuring Your Stihl Chainsaw Bar
Measuring your Stihl saw bar is not complex, but it requires precision. Follow these steps for accurate measuring Stihl saw bar results.
Step 1: Safety First!
Before you do anything, ensure your chainsaw is completely shut off, the spark plug wire is disconnected, and the chain brake is engaged. Safety is paramount when working with any power tool.
Step 2: Locate the Bar Nose
Identify the very tip of your chainsaw’s guide bar, where the chain spins.
Step 3: Find the Mounting Point
Now, look at the base of the guide bar where it connects to the chainsaw’s powerhead. There’s a specific mounting point. This is where the bar bolts onto the saw. You’ll typically see a few bolt holes here.
Step 4: The Measurement Itself
Take a measuring tape or a ruler. Place the zero mark of your measuring tape at the tip of the bar nose. Extend the tape in a straight line along the top of the bar, following its natural curve, all the way to the outside edge of the mounting point.
Important: Do not measure into the mounting holes themselves. Measure to the surface of the bar where it would meet the saw’s mounting flange.
Step 5: Record Your Measurement
Record this measurement in inches. This is the nominal length of your Stihl chainsaw bar. For example, if you measure 16 inches, your bar is a 16-inch bar.
Common Pitfalls to Avoid During Measurement
Even with simple steps, some mistakes can lead to incorrect chainsaw bar length identification.
- Measuring the Wrong Part: Some people mistakenly measure from the tip to the stud bolt hole. This is incorrect.
- Including the Sprocket: The sprocket at the tip is not part of the bar’s length measurement.
- Not Measuring Straight: The bar has a slight curve. While you follow this curve with your tape, ensure the tape is not dipping or lifting significantly.
- Not Disconnecting Power: Always ensure the spark plug wire is disconnected.
Decoding Stihl Chainsaw Bar Specifications
Beyond just length, there are other crucial numbers on your Stihl chainsaw bar that help in chainsaw bar fitting guide.
Locating the Stihl Chainsaw Bar Specifications
Stihl typically stamps these specifications directly onto the guide bar itself, usually near the mounting point or on the side of the bar. Look for numbers that indicate:
- Bar Length: The primary measurement you just took.
- Pitch: Often expressed as a fraction (e.g., 3/8″, .325″).
- Gauge: Also expressed as a fraction (e.g., .050″, .063″).
- Number of Drive Links: This is vital for ordering the correct chain.
What Do the Numbers Mean?
Let’s break down a common example: a 16-inch bar with a 3/8 pitch and .050 gauge.
- 16 inches: This is the nominal cutting length.
- 3/8: This is the pitch, meaning the distance between drive links is 3/8 of an inch.
- .050: This is the gauge, meaning the drive links are 0.050 inches thick.
Finding Your Stihl Chainsaw Model Bar Length
If you’re unsure about measuring or want to double-check, identifying your Stihl chainsaw model bar length through its model number is another effective method.
Method 1: Checking the Chainsaw Itself
Your Stihl chainsaw will have a model number clearly displayed on it, usually on a sticker or plate near the handle or on the top cover. Once you have the model number (e.g., MS250, MS391), you can:
Look it Up Online
- Visit the official Stihl website for your region.
- Navigate to the “Support” or “Product Manuals” section.
- Enter your chainsaw model number to find its manual.
- The manual will detail the recommended bar lengths and other specifications for your model.
Consult a Stihl Dealer
- Take your chainsaw model number to an authorized Stihl dealer.
- They can quickly access the Stihl chainsaw bar specifications and recommend the correct bar length and chain.
Method 2: Examining the Old Bar
Often, the chainsaw bar length identification chart details are etched onto the bar itself. Even if worn, you can often discern the numbers.
- Tip: Clean the bar thoroughly with a degreaser and a wire brush to reveal any faded markings.
Understanding Chainsaw Chain Pitch and Gauge
This is a critical part of chainsaw bar measurement that directly impacts chain compatibility.
Pitch Explained
The pitch is the distance between any three consecutive rivets on the chain, divided by two. It’s a measurement of the chain’s size. Common pitches for Stihl chainsaws include:
- 1/4″ (0.250″): Often used on smaller, lightweight saws for carving or detailed work.
- .325″: A very common pitch for many homeowner and professional saws, offering a good balance of power and speed.
- 3/8″ (0.375″): Another popular pitch, often found on more powerful saws, providing efficient cutting.
- 3/8″ Rapid Micro (RM): A lower-profile 3/8″ pitch, often used for lighter-duty saws, designed for less kickback.
- 0.404″: Typically found on large, professional-grade chainsaws for demanding timber harvesting.
Gauge Explained
The gauge refers to the thickness of the drive links, which fit into the groove of the guide bar. It’s a crucial measurement for ensuring the chain sits correctly in the bar. Common gauges include:
- .043″ (1.1mm): Thin and often used with lower-profile chains to reduce weight and kickback.
- .050″ (1.3mm): A very common gauge for a wide range of Stihl saws.
- .058″ (1.5mm): Another common gauge, often paired with 3/8″ pitch chains.
- .063″ (1.6mm): Generally found on heavier-duty saws and with larger pitch chains.
Why Pitch and Gauge Must Match
A mismatch in pitch or gauge will prevent the chain from seating properly in the bar groove. If the pitch is too large, the chain will be loose. If it’s too small, it might not fit at all, or it will bind, causing excessive wear on the bar, chain, and sprocket. The gauge is equally important; a drive link that is too thick won’t fit the groove, and one that is too thin will lead to a sloppy fit and rapid wear.
The Number of Drive Links: Your Chain’s Lifeline
When ordering a new chain, the number of drive links is just as important as the pitch and gauge. This is the number of teeth on the bottom of the chain that engage with the sprocket and sit within the bar groove.
How to Count Drive Links
- Remove the Chain: Carefully unhook the chain from the bar.
- Lay it Flat: Lay the chain out in a straight line.
- Count: Count each drive link – the small metal pieces that have a hole in them and are part of the chain’s structure that slides into the bar groove.
- Tip: It’s often easier to count every other drive link and then multiply by two to avoid errors.
Why This Number Matters
The number of drive links determines the length of the chain required for a specific bar. A bar of a given length can often accommodate different numbers of drive links depending on the manufacturer and the specific bar design. This is why simply measuring the bar length isn’t always enough; you need the drive link count for the correct chain.
Creating Your Own Chainsaw Bar Length Identification Chart
While Stihl has its own specific charts, you can create a basic one for your own tools. This is especially helpful if you have multiple saws or bars.
What to Include in Your Chart
For each bar you own, record:
- Chainsaw Model: (e.g., Stihl MS271)
- Bar Length (Inches): (e.g., 18)
- Pitch: (e.g., .325″)
- Gauge: (e.g., .050″)
- Number of Drive Links: (e.g., 72)
- Bar Part Number (if visible): This is the most definitive identifier.
Example Chart Entry
| Chainsaw Model | Bar Length (Inches) | Pitch | Gauge | Drive Links | Bar Part Number |
|---|---|---|---|---|---|
| Stihl MS250 | 16 | .325″ | .050″ | 66 | 3005 000 4809 |
| Stihl MS362 | 20 | 3/8″ | .063″ | 75 | 3003 000 6111 |
This personal chainsaw bar length identification chart will save you time and prevent ordering errors in the future.
Advanced Considerations for Chainsaw Bar Fitting
When you want to change your bar length or are working with an aftermarket bar, a deeper dive into the specifications is needed.
Aftermarket Bars vs. OEM Stihl Bars
While aftermarket bars can be a cost-effective option, it’s crucial to ensure they are designed to OEM (Original Equipment Manufacturer) specifications for your Stihl model. A poorly manufactured bar can lead to poor performance and safety issues. Always check if the aftermarket bar specifies compatibility with your specific Stihl model.
Compatibility and Stihl Chainsaw Model Bar Length
- Mounting Type: Stihl uses several different mounting types for their guide bars. Even if two bars have the same length, pitch, and gauge, they might not mount to your saw if the mounting bracket is different. Always confirm the mounting type matches your saw. Your Stihl manual or a dealer can help identify this.
- Chain Catcher: Ensure the bar has a properly functioning chain catcher, which is a safety feature designed to stop a derailed chain from whipping back towards the operator.
- Lubrication Holes: The bar needs proper oiling to keep the chain and sprocket lubricated. Ensure the bar has adequate oiling holes that align with your saw’s oiler.
How to Check Chainsaw Bar Compatibility
- Identify Your Saw’s Mount: This is the most critical step. Look at how your current bar attaches to the saw. Stihl uses various mounting patterns, often identified by a letter or number code. Your saw’s manual is the best source for this.
- Match Bar Specifications: Ensure the new bar’s pitch, gauge, and drive link count match the chain you intend to use.
- Confirm Bar Length: Choose a length that is suitable for your saw’s power and your cutting needs. Going significantly longer than recommended can overwork the engine and drivetrain.
Changing Your Chainsaw Bar Length: What to Know
You might want to change your bar length for different cutting tasks.
Can I put a longer/shorter bar on my Stihl chainsaw?
Yes, you often can, but with caveats.
- Power: A longer bar requires more power from the engine to drive the chain effectively. If you put a significantly longer bar on a smaller saw, it will bog down and struggle, potentially overheating and damaging the engine.
- Chain Compatibility: Ensure the longer or shorter bar uses the same pitch, gauge, and importantly, the same mounting type as your original bar.
- Chain Length: A longer bar requires a longer chain with more drive links. A shorter bar needs a shorter chain with fewer drive links.
- Balance and Ergonomics: A much longer or shorter bar can affect the balance and feel of the saw, potentially making it more awkward or fatiguing to use.
Maximum Recommended Bar Length
Always consult your Stihl owner’s manual for the maximum recommended bar length for your specific model. Exceeding this can lead to reduced performance and potential damage. For instance, a Stihl MS250 is typically designed for up to a 18-inch bar, but the standard is often 16 inches. Putting a 20-inch bar on it would be pushing its limits.
Frequently Asked Questions (FAQ)
Q1: How do I know what chain to get for my Stihl chainsaw bar?
A: You need to know your bar’s pitch, gauge, and the number of drive links. These specifications are usually stamped on the bar itself. If not, check your chainsaw’s model number.
Q2: Can I use a different brand of bar on my Stihl chainsaw?
A: Yes, but ensure it’s specifically designed for your Stihl model and matches the mounting type, pitch, gauge, and recommended bar length. Quality aftermarket bars are available, but always buy from reputable sources.
Q3: What happens if I use the wrong gauge chain?
A: The drive links of the chain will not fit correctly into the bar groove. Too thick a gauge will prevent the chain from seating, while too thin a gauge will result in a loose fit, excessive wear on the bar and chain, and potential derailment.
Q4: Is the bar length measured to the tip or to the curve?
A: The bar length is measured from the tip of the nose to the mounting point where the bar attaches to the saw. It’s a straight-line measurement along the top of the bar.
Q5: Where can I find a Stihl chainsaw bar length identification chart?
A: The most reliable place is your Stihl owner’s manual for your specific chainsaw model. Authorized Stihl dealers also have access to this information. You can also find general chainsaw bar size guide information online from Stihl retailers or chainsaw parts suppliers.
Q6: My bar is worn out. How do I choose a new one?
A: If your old bar is worn (groove is widened, edges are rounded), you need a direct replacement. Measure your old bar, check its markings for pitch and gauge, and count the drive links. Ensure the new bar has the same mounting type for your saw.
By following these detailed steps and paying attention to the crucial specifications, you can confidently measure your Stihl chainsaw bar length and ensure you select the correct replacement parts, keeping your saw running smoothly and safely.