How To Measure Chainsaw Bar Length Stihl (3 Pro Tips)

I once saw a guy try to fell a massive oak with a chainsaw bar that was comically too short. He spent hours hacking away, the saw bouncing and kicking, creating a dangerous and inefficient mess. It was painful to watch, and it drove home the crucial point: knowing how to measure your chainsaw bar length is fundamental to safe and effective woodcutting. It’s not just about getting the right size; it’s about understanding the capabilities of your saw and ensuring you’re working within its limits. In this guide, I’ll share my expertise, honed over years of working with chainsaws, on how to accurately measure your Stihl chainsaw bar length and offer three pro tips to help you choose the right size for your needs.

How to Measure Chainsaw Bar Length Stihl (3 Pro Tips)

Why Chainsaw Bar Length Matters

Before diving into the “how,” let’s discuss the “why.” The length of your chainsaw bar directly impacts:

Cutting Capacity: A longer bar allows you to cut thicker logs.
Saw Control: A bar that’s too long for your saw’s engine can lead to poor performance and increased risk of kickback.
Safety: Using the appropriate bar length reduces strain on the saw and the operator, contributing to a safer work environment.
Efficiency: Matching the bar length to the task at hand optimizes cutting speed and reduces wasted energy.

Think of it like this: a small engine trying to power a huge bar is like trying to drive a tiny car uphill while towing a massive trailer. It’s going to struggle, overheat, and potentially break down. A properly sized bar, on the other hand, allows your saw to operate efficiently and safely.

Key Terms:

Chainsaw Bar: The metal guide that supports and directs the chainsaw chain.
Cutting Length: The usable length of the bar exposed for cutting. This is what we’re measuring.
Pitch: The distance between three consecutive rivets on the chain, divided by two. This is crucial for matching the chain to the bar.
Gauge: The thickness of the drive links on the chain that fit into the groove of the bar. Again, essential for compatibility.
Kickback: A dangerous event where the chainsaw suddenly kicks back towards the operator. Often caused by improper bar length or technique.

Step-by-Step Guide to Measuring Your Stihl Chainsaw Bar Length

Here’s how I measure my Stihl chainsaw bars, and how you can do it too.

Tools You’ll Need:

Measuring tape or ruler (preferably a metal one for accuracy)
Gloves (for handling the chainsaw safely)
A clean, flat surface
Your Stihl chainsaw (with the bar attached)

Safety First:

Always wear gloves when handling a chainsaw bar. The chain is sharp, even when not in motion.
Ensure the chainsaw is turned off and the spark plug is disconnected before performing any maintenance or measurements.
Work in a well-lit area to avoid accidents.

Step 1: Identify the Cutting Length

The most important concept to understand is that we’re measuring the cutting length, not the total length of the bar. The cutting length is the portion of the bar that’s actually exposed and usable for cutting. This excludes the part of the bar that’s housed inside the chainsaw body.

Step 2: Locate the Measurement Point

The measurement starts from the point where the bar emerges from the chainsaw body. This is usually right where the chain exits the housing.

Step 3: Measure to the Tip

Extend your measuring tape from the point where the bar emerges from the chainsaw body to the tip of the bar. Make sure the tape is straight and taut for an accurate measurement.

Step 4: Record the Measurement

Note the measurement in inches. This is your chainsaw bar’s cutting length. For example, you might find it’s 16 inches, 18 inches, or 20 inches. Stihl chainsaw bars typically come in even-numbered sizes.

Step 5: Verify Against the Bar Stamp

Most chainsaw bars have the length stamped directly on them. Look closely at the base of the bar, near where it mounts to the chainsaw. You should find a number, often followed by “IN” (for inches). This is the manufacturer’s stated bar length. Compare this to your measurement. They should be very close. If there’s a significant discrepancy, re-measure to ensure accuracy.

Example:

Let’s say I’m measuring my Stihl MS 271 chainsaw. I follow the steps above and find that the cutting length is 18 inches. I then check the bar itself and find a stamp that reads “18 IN.” This confirms that I’ve measured correctly.

Pro Tip 1: Understanding Stihl Bar Mounts and Compatibility

Stihl chainsaws use different bar mount patterns. This means a bar that fits one Stihl model might not fit another. It’s crucial to understand your chainsaw’s mount pattern to ensure compatibility.

How to Identify Your Stihl Mount Pattern:

Consult Your Owner’s Manual: This is the best source of information. It will clearly state the compatible bar mount type for your specific model.
Check Stihl’s Website: Stihl’s website has detailed information on chainsaw specifications, including bar mount types.
Compare to an Existing Bar: If you have an existing bar that fits your chainsaw, you can use it as a reference. Compare the shape and size of the mount to potential replacements.

Common Stihl Mount Patterns:

Small Stihl Mount: Used on smaller models like the MS 170, MS 180, and MS 194 T.
Large Stihl Mount: Used on larger models like the MS 261, MS 271, MS 291, MS 362, and MS 462.
3003 Mount: A common mount used on many professional-grade Stihl chainsaws.

Why This Matters:

Using an incompatible bar mount can damage your chainsaw and potentially cause serious injury. The bar might not seat properly, leading to chain misalignment and increased risk of kickback. Always verify the mount compatibility before purchasing a new bar.

Personal Experience:

I once tried to fit a bar with a large Stihl mount onto a chainsaw that used a small Stihl mount. The bar simply wouldn’t fit. The bolt holes didn’t align, and the bar was too wide to properly seat on the chainsaw body. I quickly realized my mistake and avoided potentially damaging my saw.

Pro Tip 2: Choosing the Right Bar Length for the Job

Selecting the appropriate bar length depends on the type of cutting you’ll be doing. Here’s a general guideline:

Small Chainsaws (14-16 inch bar): Ideal for pruning, limbing, and cutting small trees (up to 12 inches in diameter). These saws are lightweight and easy to maneuver, making them perfect for tasks that require precision.
Medium Chainsaws (18-20 inch bar): Suitable for felling medium-sized trees (up to 16 inches in diameter), bucking firewood, and general yard work. These saws offer a good balance of power and maneuverability.
Large Chainsaws (20+ inch bar): Designed for felling large trees (over 16 inches in diameter), cutting thick logs, and heavy-duty tasks. These saws require more experience and strength to operate safely.

Factors to Consider:

Tree Diameter: The most important factor. Your bar length should be at least slightly longer than the diameter of the trees you plan to cut. This allows you to fell trees in a single pass, which is safer and more efficient.
Saw Power: Don’t overload your chainsaw with a bar that’s too long. A longer bar requires more power to drive the chain, and if your saw doesn’t have enough power, it will struggle to cut effectively.
User Experience: If you’re a beginner, start with a shorter bar. It will be easier to control and less likely to kick back. As you gain experience, you can gradually increase the bar length.
Type of Wood: Hardwoods like oak and maple require more power to cut than softwoods like pine and fir. If you’re cutting hardwoods, you might need a larger saw and a longer bar.

Case Study: Firewood Preparation

I primarily use my Stihl MS 271 with an 18-inch bar for preparing firewood. This setup allows me to efficiently buck logs up to 16 inches in diameter, which is the typical size of the firewood I process. I find that the 18-inch bar provides a good balance of cutting capacity and maneuverability, making it ideal for this task.

Data Point:

According to a study by the U.S. Forest Service, the average diameter of firewood logs is between 8 and 12 inches. This suggests that a 16-18 inch bar is sufficient for most firewood preparation tasks.

Strategic Advantage:

Choosing the right bar length for your needs can significantly improve your efficiency and reduce fatigue. A properly sized bar allows you to cut faster, with less effort, and with a lower risk of injury.

Pro Tip 3: Maintaining Your Chainsaw Bar for Longevity and Safety

Proper maintenance is essential for extending the life of your chainsaw bar and ensuring safe operation. Here are some key maintenance tasks:

Regular Cleaning: After each use, clean the bar with a wire brush to remove sawdust, pitch, and debris. This prevents the chain from binding and reduces wear on the bar.
Chain Sharpening: A sharp chain is crucial for efficient cutting and safety. Sharpen the chain regularly using a chainsaw file or a chain grinder. A dull chain requires more force to cut, increasing the risk of kickback.
Bar Oiling: Ensure that the bar oiler is functioning properly and that the bar is receiving adequate lubrication. Insufficient lubrication can cause the chain to overheat and damage the bar.
Bar Dressing: Periodically dress the bar with a flat file to remove burrs and restore the groove to its proper shape. This ensures that the chain runs smoothly and prevents premature wear.
Chain Tension: Maintain proper chain tension. A chain that’s too loose can derail, while a chain that’s too tight can overheat and damage the bar and chain.
Bar Flipping: Regularly flip the bar over to distribute wear evenly. This helps to prolong the life of the bar.

Tools for Bar Maintenance:

Wire Brush: For cleaning sawdust and debris.
Chainsaw File: For sharpening the chain.
Chain Grinder: For more precise chain sharpening.
Flat File: For dressing the bar.
Bar Groove Cleaner: A specialized tool for cleaning the bar groove.

Personal Experience:

I once neglected to properly clean and oil my chainsaw bar after a particularly dusty cutting session. The bar became clogged with sawdust, and the chain started to bind. This caused the chain to overheat and eventually break. I learned my lesson the hard way and now make sure to thoroughly clean and lubricate my bar after each use.

Data Point:

According to a study by Oregon Products, proper chain maintenance can extend the life of a chainsaw bar by up to 50%.

Strategic Advantage:

Investing in proper bar maintenance can save you money in the long run by extending the life of your bar and preventing costly repairs. It also improves the performance of your chainsaw and reduces the risk of accidents.

Understanding Wood Types and Their Impact on Chainsaw Use

The type of wood you’re cutting significantly impacts the performance of your chainsaw and the choice of bar length. Different wood types have varying densities, moisture content, and resin levels, all of which affect cutting efficiency.

Key Concepts:

Green Wood: Freshly cut wood that has a high moisture content (typically above 30%). Green wood is generally easier to cut than seasoned wood but can be heavier and more prone to warping.
Seasoned Wood: Wood that has been allowed to dry for a period of time, reducing its moisture content (typically below 20%). Seasoned wood is lighter, more stable, and burns more efficiently in a fireplace or wood stove.
Hardwood: Wood from deciduous trees (e.g., oak, maple, ash) that is generally denser and harder to cut than softwood. Hardwoods are typically used for furniture, flooring, and high-heat firewood.
Softwood: Wood from coniferous trees (e.g., pine, fir, spruce) that is generally less dense and easier to cut than hardwood. Softwoods are commonly used for construction, paper production, and lower-heat firewood.

Wood Type and Bar Length:

Cutting Softwood: A shorter bar (14-16 inches) is often sufficient for cutting softwood, as it requires less power to cut through.
Cutting Hardwood: A longer bar (18-20+ inches) may be necessary for cutting hardwood, especially if the wood is dense and dry.
Cutting Green Wood: Green wood can be easier to cut due to its high moisture content, but it can also be more prone to binding. Ensure your chain is sharp and your bar is properly lubricated.
Cutting Seasoned Wood: Seasoned wood can be more challenging to cut due to its hardness and dryness. Use a sharp chain and apply consistent pressure.

Example:

I once tried to cut a large oak log that had been seasoned for several years with a chainsaw that had a dull chain and a bar that was too short. The saw struggled to cut through the wood, and the chain kept binding. I quickly realized that I needed to sharpen the chain and switch to a longer bar to effectively cut the log.

Data Point:

According to the Wood Handbook published by the U.S. Forest Products Laboratory, the density of oak is approximately 45 pounds per cubic foot, while the density of pine is approximately 30 pounds per cubic foot. This illustrates the significant difference in density between hardwoods and softwoods.

Strategic Advantage:

Understanding the properties of different wood types allows you to choose the appropriate chainsaw and bar length for the job, improving your efficiency and reducing the risk of damage to your equipment.

Felling Techniques and Bar Length

The technique you use for felling a tree is also influenced by the bar length of your chainsaw.

Key Felling Techniques:

Conventional Felling: This involves making a notch on the side of the tree in the direction you want it to fall, followed by a back cut that leaves a hinge of wood to control the fall.
Hinge Wood: The strip of wood left uncut during felling, controlling the direction of the fall. The size and shape of the hinge are critical for safe and predictable felling.
Boring Cut: A technique used to create a bore cut through the center of the tree before making the felling cut. This is particularly useful for larger trees or trees with lean.

Bar Length and Felling Technique:

Shorter Bar (14-16 inches): Suitable for felling smaller trees using the conventional felling technique.
Longer Bar (18-20+ inches): Necessary for felling larger trees, especially when using the boring cut technique. A longer bar allows you to reach the center of the tree and create a controlled bore cut.

Example:

I recently felled a large maple tree that was leaning significantly in the wrong direction. I used a chainsaw with a 24-inch bar to create a bore cut through the center of the tree, which allowed me to safely control the direction of the fall. If I had used a chainsaw with a shorter bar, I would not have been able to make the bore cut, and the tree could have fallen in an unpredictable and dangerous manner.

Data Point:

According to the Occupational Safety and Health Administration (OSHA), improper felling techniques are a leading cause of chainsaw-related injuries. Using the appropriate bar length and felling technique can significantly reduce the risk of accidents.

Strategic Advantage:

Choosing the right bar length and felling technique can improve the safety and efficiency of your felling operations. A longer bar can provide more control when felling larger trees, while a shorter bar can be more maneuverable for felling smaller trees.

Chainsaw Safety: A Constant Priority

No discussion about chainsaws is complete without emphasizing safety. Chainsaws are powerful tools that can cause serious injury if not used properly.

Key Safety Considerations:

Personal Protective Equipment (PPE): Always wear appropriate PPE, including a helmet, eye protection, hearing protection, gloves, chaps, and steel-toed boots.
Kickback Awareness: Be aware of the risk of kickback and take steps to prevent it. Keep the chain sharp, avoid cutting with the tip of the bar, and maintain a firm grip on the chainsaw.
Proper Stance: Maintain a stable stance with your feet shoulder-width apart and your weight evenly distributed.
Safe Cutting Techniques: Use proper cutting techniques to avoid binding and kickback.
Clear Work Area: Clear the work area of obstacles and ensure that you have a clear escape route.
Regular Maintenance: Keep your chainsaw properly maintained and inspected regularly.
Training: Seek professional training on chainsaw safety and operation.

Personal Experience:

I once witnessed a serious chainsaw accident where a worker was injured when the chainsaw kicked back and struck him in the leg. The worker was not wearing chaps, and he suffered a severe laceration. This incident reinforced the importance of always wearing appropriate PPE and following safe operating procedures.

Data Point:

According to the Consumer Product Safety Commission (CPSC), there are approximately 30,000 chainsaw-related injuries each year in the United States. Many of these injuries could be prevented by following basic safety precautions.

Strategic Advantage:

Prioritizing safety is not only the right thing to do, but it also improves your productivity and reduces the risk of costly accidents. A safe work environment is a more efficient and productive work environment.

Beyond the Bar: Chainsaw Chain Selection

While the bar length is critical, the chainsaw chain is equally important for optimal performance. The chain type, pitch, and gauge must be compatible with your chainsaw and the type of wood you’re cutting.

Key Chain Characteristics:

Pitch: The distance between three consecutive rivets on the chain, divided by two. Common pitches include .325 inch, 3/8 inch, and .404 inch.
Gauge: The thickness of the drive links on the chain that fit into the groove of the bar. Common gauges include .050 inch, .058 inch, and .063 inch.
Chain Type: Different chain types are designed for different applications. Common chain types include full chisel, semi-chisel, and low-kickback chains.

Chain Selection and Bar Length:

Matching Pitch and Gauge: The chain’s pitch and gauge must match the bar’s specifications. Using an incompatible chain can damage the bar and chain.
Chain Type and Wood Type: Choose a chain type that is appropriate for the type of wood you’re cutting. Full chisel chains are best for cutting clean wood, while semi-chisel chains are more durable for cutting dirty or knotty wood. Low-kickback chains are recommended for beginners.
Chain Length: The chain must be the correct length for the bar. The number of drive links is typically specified on the bar.

Example:

I recently replaced the chain on my Stihl MS 271 with a chain that had the wrong pitch. The chain didn’t fit properly on the bar, and it kept derailing. I quickly realized my mistake and switched to a chain with the correct pitch.

Data Point:

According to a study by the Chain Saw Manufacturers Association (CSMA), using the correct chain can improve cutting efficiency by up to 20%.

Strategic Advantage:

Selecting the right chainsaw chain can improve your cutting performance, extend the life of your bar and chain, and reduce the risk of accidents.

Final Thoughts and Next Steps

Measuring your chainsaw bar length is a fundamental skill for anyone working with wood. By following the steps outlined in this guide and understanding the pro tips, you can ensure that you’re using the right bar length for your needs, improving your safety, efficiency, and the longevity of your equipment.

Next Steps:

Measure your existing chainsaw bar: Use the step-by-step guide to accurately measure the cutting length of your current bar.
Identify your Stihl mount pattern: Consult your owner’s manual or Stihl’s website to determine the correct mount pattern for your chainsaw.
Assess your cutting needs: Consider the type of cutting you’ll be doing (pruning, felling, firewood preparation) and the diameter of the trees you plan to cut.
Choose the right bar length: Select a bar length that is appropriate for your needs and your chainsaw’s capabilities.
Inspect your bar and chain: Regularly inspect your bar and chain for wear and damage, and perform necessary maintenance.
Practice safe chainsaw operation: Always wear appropriate PPE and follow safe operating procedures.
Consider taking a chainsaw safety course: Gain valuable knowledge and skills from experienced professionals.

By taking these steps, you can become a more skilled and confident chainsaw operator, ensuring that you’re working safely and efficiently. Remember, knowledge and preparation are your best tools when working with chainsaws.

How to Measure Chainsaw Bar Length Stihl (3 Pro Tips)