Chainsaw Stihl 20 Inch Guide (5 Expert Tips for Ideal Bar Use)

Chainsaw Stihl 20 Inch Guide: 5 Expert Tips for Ideal Bar Use

As a seasoned woodcutter, I’ve spent countless hours with a chainsaw in my hands, felling trees, bucking logs, and preparing firewood. The Stihl chainsaw, particularly with a 20-inch bar, has been a reliable workhorse throughout my career. In this guide, I’m sharing five expert tips for maximizing the performance and lifespan of your 20-inch Stihl chainsaw bar, drawing from my personal experiences and technical knowledge. These tips aren’t just theory; they’re grounded in real-world application and proven techniques that will help you cut smarter, safer, and more efficiently.

1. Choosing the Right Chain for Your Stihl 20-Inch Bar

Selecting the correct chain for your Stihl 20-inch bar is paramount. It’s not a one-size-fits-all situation. Factors like the type of wood you’re cutting, the desired cutting speed, and the level of kickback protection all play a role.

• Chain Pitch: The pitch is the distance between any three consecutive rivets divided by two. Common pitches for Stihl chainsaws include .325″, 3/8″ and .404″. The 20-inch bar can accommodate different pitches depending on the chainsaw model. Refer to your chainsaw’s manual for the recommended pitch. Using the wrong pitch can damage the bar and chain and render the saw unusable.
• Chain Gauge: The gauge refers to the thickness of the drive links that fit into the bar groove. Common gauges are .050″, .058″ and .063″. Again, your chainsaw model will dictate the appropriate gauge. Mismatched gauge leads to improper chain seating and increased wear.
• Chain Type:
  • Full Chisel: These chains have aggressive cutters and offer the fastest cutting speed, ideal for softwoods like pine and fir. However, they require more skill to use and are more prone to kickback.
  • Semi-Chisel: A good compromise between cutting speed and durability. These chains are more forgiving and suitable for hardwoods like oak and maple, as well as dirty or knotty wood.
  • Low-Kickback: Designed with features that reduce the risk of kickback, making them a safer option for novice users. They typically have bumper drive links or guard links.

Personal Experience: I once used a full chisel chain on a seasoned oak log, thinking I could speed up the process. The aggressive cutters dulled almost instantly due to the hardness of the wood, and the increased vibration made the task much more tiring. I quickly switched to a semi-chisel chain, and the difference was night and day. The semi-chisel chain handled the hardwood with ease, and the vibration was significantly reduced.

Technical Data:

• Wood Hardness (Janka Scale): Softwoods generally range from 150-700 lbf, while hardwoods can range from 1000-2000+ lbf. This directly impacts chain selection.
• Chain Speed: Full chisel chains can achieve up to 20% faster cutting speeds in softwoods compared to semi-chisel chains.
• Kickback Reduction: Low-kickback chains can reduce kickback force by up to 50% compared to standard chains.

Practical Tip: If you’re unsure which chain is right for you, consult your Stihl dealer. They can assess your needs and recommend the best option. Always prioritize safety by choosing a low-kickback chain if you’re a beginner or working in tight spaces.

2. Mastering Proper Chain Tensioning

Correct chain tension is crucial for efficient cutting, bar longevity, and operator safety. Too loose, and the chain can derail, causing damage and potential injury. Too tight, and it can overheat, leading to premature wear on the bar and chain, as well as reduced cutting power.

• Checking Tension: Before each use, and periodically during use, check the chain tension. The chain should be snug against the underside of the bar, but you should still be able to pull it around the bar by hand.
• Tensioning Procedure:
  1. Loosen the bar nuts that secure the bar cover.
  2. Use a scrench (a combination wrench and screwdriver) to adjust the tensioning screw. Turn it clockwise to tighten the chain and counter-clockwise to loosen it.
  3. Tighten the bar nuts securely after achieving the correct tension.
• Hot Tensioning: When the chain is hot from use, it will expand. Adjust the tension slightly looser than you would when the chain is cold. As the chain cools, it will contract and tighten.

Personal Experience: I remember a time when I was cutting firewood all day, and I neglected to check the chain tension. The chain became increasingly loose, and eventually, it derailed while I was bucking a log. The chain whipped around and struck my leg, thankfully protected by chaps. This incident taught me the importance of regular chain tension checks and the value of wearing proper safety gear.

Technical Data:

• Chain Expansion: A chainsaw chain can expand by up to 0.02 inches per foot of bar length when heated during use.
• Tension Measurement: The ideal chain tension allows for approximately 1/8 inch of sag on the underside of the bar when the chain is cold.
• Bar Groove Width: The bar groove width must match the chain gauge. Using a chain with a smaller gauge than the bar groove can lead to excessive chain movement and premature wear.

Practical Tip: After tensioning the chain, always rotate it by hand to ensure it moves freely. If the chain feels tight or binds, re-adjust the tension until it moves smoothly. It’s better to err on the side of slightly too loose than too tight.

3. Optimizing Bar Lubrication for Peak Performance

Proper lubrication is the lifeblood of your chainsaw bar and chain. It reduces friction, dissipates heat, and prevents premature wear. Insufficient lubrication leads to rapid bar and chain deterioration, decreased cutting efficiency, and increased risk of chain breakage.

• Oil Type: Use a high-quality bar and chain oil specifically formulated for chainsaws. These oils contain additives that improve lubricity, reduce fling-off, and protect against rust and corrosion. Avoid using motor oil or other substitutes, as they may not provide adequate lubrication and can damage the bar and chain.
• Oil Level: Check the oil reservoir before each use and refill as needed. The oil level should be sufficient to provide a continuous flow of oil to the bar and chain during operation.
• Oiler Function: Ensure the oiler is functioning correctly. Most Stihl chainsaws have an adjustable oiler that allows you to control the oil flow rate. Adjust the oiler according to the wood type and cutting conditions. Hardwoods and heavy cutting require more oil than softwoods and light cutting.
• Oil Hole Maintenance: Regularly clean the oil hole on the bar to prevent clogging. Debris and sawdust can accumulate in the oil hole, restricting oil flow. Use a small wire or pick to clear any obstructions.

Personal Experience: I once neglected to check the oil level before starting a large felling project. Midway through the job, I noticed the chain was smoking and cutting poorly. I quickly realized the oil reservoir was empty. The bar and chain were severely overheated, and the bar suffered permanent damage. I learned my lesson the hard way – always check the oil level!

Technical Data:

• Oil Flow Rate: The recommended oil flow rate for a 20-inch bar is typically between 0.5 and 1.0 fluid ounces per minute.
• Oil Viscosity: Bar and chain oil typically has a viscosity grade of ISO VG 68 or ISO VG 100.
• Friction Reduction: Proper lubrication can reduce friction between the chain and bar by up to 80%.
• Heat Dissipation: Bar and chain oil helps dissipate heat generated during cutting, preventing the bar and chain from overheating.

Practical Tip: To check if the oiler is working correctly, start the chainsaw and hold it over a piece of cardboard or a stump. After a few seconds, you should see a spray of oil coming off the chain. If no oil is visible, check the oil level, oil hole, and oiler adjustment.

4. Maintaining Bar Groove and Rails

The bar groove and rails are critical components of the chainsaw bar. The groove guides the chain, and the rails support the chain cutters. Maintaining these surfaces ensures smooth chain movement, efficient cutting, and extended bar life.

• Cleaning the Groove: Regularly clean the bar groove to remove sawdust, debris, and accumulated oil. Use a bar groove cleaner or a flat screwdriver to scrape out the groove. A clogged groove can restrict chain movement and cause premature wear.
• Dressing the Rails: The bar rails can become worn or damaged over time, leading to uneven chain contact and reduced cutting performance. Use a bar rail dresser or a flat file to restore the rails to their original shape. File the rails evenly, removing any burrs or sharp edges.
• Squaring the Bar: Over time, the bar can become bent or twisted, especially if it’s been pinched or subjected to excessive force. Use a bar straightener to realign the bar and restore its original shape.
• Checking for Wear: Inspect the bar regularly for signs of wear, such as rounded rails, a widened groove, or excessive scoring. If the bar is severely worn, it’s time to replace it.

Personal Experience: I once had a chainsaw bar that was cutting poorly, even after sharpening the chain. I inspected the bar and discovered that the rails were severely rounded. I used a bar rail dresser to restore the rails to their original shape, and the difference was remarkable. The chainsaw cut like new again.

Technical Data:

• Rail Height: The ideal rail height is typically between 0.02 and 0.04 inches above the bar body.
• Groove Width Tolerance: The bar groove width should be within 0.002 inches of the chain gauge.
• Bar Hardness: Chainsaw bars are typically made from hardened steel with a Rockwell hardness of HRC 50-55.
• Rail Wear Rate: The wear rate of the bar rails depends on the wood type, cutting conditions, and lubrication. Hardwoods and abrasive materials accelerate rail wear.

Practical Tip: To check the bar groove width, use a chain gauge tool. This tool has different slots that correspond to different chain gauges. If the gauge tool fits loosely in the groove, the bar is worn and needs to be replaced.

5. Sharpening Your Chain to Perfection

A sharp chain is essential for safe and efficient cutting. A dull chain requires more force to cut, increasing the risk of kickback and operator fatigue. Regular chain sharpening is crucial for maintaining optimal cutting performance and extending the life of your bar and chain.

• Sharpening Tools: You’ll need a chainsaw file, a file guide, and a depth gauge tool. A vise is also helpful for holding the bar securely during sharpening.
• Sharpening Angle: The correct sharpening angle depends on the chain type. Refer to your chain manufacturer’s specifications for the recommended angle. Typically, the top plate angle is between 25 and 35 degrees, and the side plate angle is between 60 and 75 degrees.
• Sharpening Procedure:
  1. Secure the bar in a vise.
  2. Place the file guide on the chain cutter, aligning it with the correct sharpening angle.
  3. File the cutter from the inside out, using smooth, even strokes.
  4. Repeat the process for each cutter, maintaining a consistent angle and stroke count.
  5. Use a depth gauge tool to check the depth gauge setting. The depth gauge should be slightly lower than the cutter.
  6. File the depth gauges as needed to maintain the correct setting.
• Frequency: Sharpen your chain whenever it becomes dull or after hitting dirt or rocks. A sharp chain will pull itself into the wood, while a dull chain will require more force to push it through.

Personal Experience: I used to neglect chain sharpening, thinking it was a tedious and time-consuming task. However, I quickly realized that a sharp chain made a huge difference in cutting performance and operator fatigue. I now sharpen my chain regularly, and I can cut more wood in less time with less effort.

Technical Data:

• File Diameter: The correct file diameter depends on the chain pitch. Refer to your chain manufacturer’s specifications for the recommended file diameter.
• Depth Gauge Setting: The depth gauge setting is typically between 0.025 and 0.030 inches below the cutter.
• Sharpening Angle Tolerance: The sharpening angle should be within +/- 2 degrees of the recommended angle.
• Cutting Efficiency: A sharp chain can cut up to 50% faster than a dull chain.

Practical Tip: Use a file guide to maintain the correct sharpening angle. This will help you sharpen the chain consistently and prevent damage to the cutters. After sharpening, always check the chain tension and lubrication before using the chainsaw. * Chain Grinders: For high volume sharpening, consider using a powered chain grinder. These tools offer precise and consistent sharpening, especially for those who sharpen chains frequently. They can significantly reduce the time and effort required for sharpening.

Case Study: Optimizing Firewood Production with a Stihl 20-Inch Chainsaw

I recently undertook a project to produce firewood for the winter season. I used my Stihl chainsaw with a 20-inch bar for felling, bucking, and splitting the wood. Here’s a breakdown of the technical details and insights from the project:

• Wood Source: I sourced seasoned oak logs with an average diameter of 16 inches. The moisture content was approximately 25%, which is ideal for splitting but still requires further drying for optimal burning.
• Chainsaw Setup: I used a Stihl MS 271 chainsaw with a 20-inch bar and a semi-chisel chain. I ensured the chain was properly tensioned and lubricated before each use.
• Cutting Techniques: I employed proper felling techniques, including making a notch cut and a back cut. For bucking, I used a sawbuck to support the logs and prevent pinching.
• Splitting Process: I used a hydraulic log splitter to split the logs into firewood-sized pieces. The average piece size was 16 inches long and 6 inches in diameter.
• Drying Process: I stacked the firewood in a well-ventilated area to allow it to dry. The target moisture content for optimal burning is below 20%.
• Results: I produced approximately 5 cords of firewood in two weeks. The Stihl chainsaw performed flawlessly, and the 20-inch bar provided ample cutting capacity.

Technical Details:

• Log Dimensions: Average diameter: 16 inches; Length: 8-12 feet.
• Moisture Content: Initial moisture content: 25%; Target moisture content: below 20%.
• Cord Volume: 1 cord = 128 cubic feet.
• Drying Time: Oak firewood typically takes 6-12 months to dry completely.
• Chainsaw Calibration: I checked the chainsaw’s carburetor settings to ensure optimal performance. A properly calibrated carburetor ensures efficient fuel consumption and maximum power output.

Insights:

• Wood Selection: Choosing the right wood species is crucial for firewood production. Oak is a dense hardwood that provides excellent heat output.
• Moisture Content: Drying firewood to the correct moisture content is essential for efficient burning. Wet firewood produces less heat and more smoke.
• Chainsaw Maintenance: Regular chainsaw maintenance is critical for optimal performance and longevity. This includes chain sharpening, bar lubrication, and air filter cleaning.
• Safety Precautions: Always wear appropriate safety gear when operating a chainsaw, including a helmet, eye protection, hearing protection, gloves, and chaps.

By following these expert tips and implementing proper techniques, you can maximize the performance and lifespan of your Stihl 20-inch chainsaw bar and achieve your wood processing goals safely and efficiently. Remember, safety always comes first. Always wear appropriate safety gear and follow the manufacturer’s instructions. Happy cutting!

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