Stihl MS170 Chain File Size (5 Pro Tips for Precision Sharpening)

Stihl MS170 Chain File Size: 5 Pro Tips for Precision Sharpening

The Stihl MS170 is a popular chainsaw, known for its reliability and ease of use. It’s a great saw for homeowners and light-duty tasks. But, like any chainsaw, its performance relies heavily on a sharp chain. A dull chain not only makes cutting harder and slower, but it also increases the risk of kickback and other dangerous situations. Getting the right chain file size is the foundation of proper sharpening.

Understanding the Importance of Chain Sharpening

Before we get into the specifics, let’s quickly recap why sharpening your chainsaw chain is so important.

• Safety: A sharp chain cuts smoothly and efficiently, reducing the risk of kickback and other accidents. A dull chain requires more force, making it harder to control.
• Efficiency: A sharp chain cuts faster and requires less effort, saving you time and energy.
• Saw Longevity: A dull chain puts extra strain on the chainsaw motor, potentially shortening its lifespan.
• Cut Quality: A sharp chain produces cleaner cuts, which is especially important for woodworking or projects where aesthetics matter.
• Fuel Efficiency: A sharp chain requires less power to cut, which translates to better fuel efficiency.

Determining the Correct File Size for Your Stihl MS170 Chain

This is the most crucial step. Using the wrong file size can damage your chain and reduce its cutting performance. The Stihl MS170 typically uses a chain with a 3/8″ low profile pitch. This means the links of the chain are spaced 3/8 of an inch apart.

The correct file size for most 3/8″ low profile chains, including those used on the Stihl MS170, is typically a 5/32″ (4.0 mm) round file.

However, always double-check your chain’s specifications. The best way to do this is to consult your chainsaw’s owner’s manual or look for markings on the chain itself. The chain manufacturer sometimes stamps the recommended file size directly onto the chain. If you’re still unsure, take your chain to a local chainsaw dealer. They can quickly identify the correct file size for you.

Why is the file size so important?

• Too Small: A file that’s too small won’t properly sharpen the cutting edges of the teeth.
• Too Large: A file that’s too large can damage the chain by rounding over the cutting edges or creating an incorrect cutting angle.

My Experience: I once tried to sharpen a chain with a file that was slightly too large. The result was a chain that looked sharp but didn’t cut well. It would grab and chatter, making it very difficult to control the saw. I ended up having to replace the chain.

Pro Tip 1: Invest in Quality Files and Tools

Don’t skimp on your sharpening tools. Cheap files will dull quickly and won’t produce a clean, sharp edge. Invest in quality files made from high-carbon steel. I personally prefer Pferd or Stihl files, as they hold their edge well and provide consistent results.

Here’s what I recommend:

• Round Files: Get a few 5/32″ (4.0 mm) round files from a reputable brand.
• Flat File: You’ll need a flat file for adjusting the depth gauges (rakers).
• File Guide: A file guide helps you maintain the correct sharpening angle and depth. While you can sharpen freehand, a guide is highly recommended, especially for beginners.
• Depth Gauge Tool: This tool is used to check and adjust the height of the depth gauges.
• Vise: A small vise to hold the chainsaw bar steady while sharpening is very helpful. A dedicated chainsaw vise that clamps onto a stump or log is ideal for field sharpening.
• Gloves: Protect your hands from sharp teeth.

Tool Specifications and Costs:

Case Study: I once worked on a project clearing a large area of overgrown brush. We were using several chainsaws, including a Stihl MS170. One of the crew members was using a cheap file that he had picked up at a discount store. His chain was constantly dull, and he was struggling to keep up with the rest of the team. I gave him one of my Pferd files, and the difference was immediately noticeable. He was able to sharpen his chain quickly and easily, and his cutting performance improved dramatically.

Pro Tip 2: Master the Sharpening Angle and Technique

The correct sharpening angle is crucial for achieving a sharp and durable cutting edge. The Stihl MS170 typically uses a chain with a 30-degree sharpening angle and a 10-degree down angle.

Here’s how to sharpen using the correct angles:

1. Secure the Chain: Place your chainsaw in a vise or use a bar-mounted vise to hold the bar securely. Make sure the chain is free to move.
2. Position the File: If you’re using a file guide, align it with the chain so that the file sits at the correct angle. If you’re sharpening freehand, use your eye to estimate the correct angle.
3. Sharpen the Teeth: Using smooth, even strokes, file each tooth from the inside out. Apply light pressure on the forward stroke and release pressure on the return stroke.
4. Count Your Strokes: Sharpen each tooth with the same number of strokes to ensure consistent sharpening. I usually aim for 3-5 strokes per tooth.
5. Sharpen All Teeth on One Side: Once you’ve sharpened all the teeth on one side of the chain, rotate the chainsaw in the vise and sharpen the teeth on the other side.
6. Check Your Work: After sharpening, visually inspect each tooth to ensure that it has a sharp, clean edge.

Key Concepts:

• Sharpening Angle: The angle at which the file meets the cutting edge of the tooth.
• Down Angle: The angle at which the file is tilted downward.
• Consistent Strokes: Using the same number of strokes on each tooth ensures that they are all sharpened to the same degree.

Measurements and Specifications:

• Sharpening Angle: 30 degrees (typically)
• Down Angle: 10 degrees (typically)
• Stroke Length: 1-2 inches

My Experience: When I first started sharpening chainsaws, I struggled to maintain the correct sharpening angle. My cuts were often uneven and the chain would dull quickly. Using a file guide made a huge difference. It helped me to maintain the correct angle and depth, resulting in a much sharper and more durable chain.

Pro Tip 3: Don’t Forget the Depth Gauges (Rakers)

The depth gauges, also known as rakers, control how much wood each tooth can cut. If the depth gauges are too high, the chain won’t cut effectively. If they’re too low, the chain will grab and chatter.

Here’s how to check and adjust the depth gauges:

1. Use a Depth Gauge Tool: Place the depth gauge tool on top of the chain, aligning it with the depth gauge you want to check.
2. Check the Height: If the depth gauge protrudes above the tool, it needs to be filed down.
3. File Down the Depth Gauge: Using a flat file, carefully file down the depth gauge until it is flush with the top of the depth gauge tool.
4. Round Off the Front: After filing down the depth gauge, use the flat file to slightly round off the front edge of the depth gauge. This will help to prevent the chain from grabbing.

Key Concepts:

• Depth Gauge: The part of the chain that controls the depth of the cut.
• Raker: Another name for the depth gauge.
• Depth Gauge Tool: A tool used to check and adjust the height of the depth gauges.

Measurements and Specifications:

• Depth Gauge Setting: Typically 0.025″ – 0.030″ below the cutting edge (consult your owner’s manual)

My Experience: I once had a chainsaw that was cutting very slowly, even after I had sharpened the chain. I checked the depth gauges and found that they were all too high. After filing them down to the correct height, the chainsaw cut like new.

Case Study: A local tree service company was experiencing problems with their chainsaws cutting slowly. They were constantly sharpening their chains, but the saws still weren’t performing well. I went out to their shop and found that they were neglecting to adjust the depth gauges. After showing them how to properly check and adjust the depth gauges, their chainsaw performance improved dramatically. They were able to cut more wood with less effort, and their chains lasted longer.

Pro Tip 4: Clean Your Chain and Bar Regularly

A clean chain and bar will cut more efficiently and last longer. Sawdust and pitch can build up on the chain and bar, causing friction and heat.

Here’s how to clean your chain and bar:

1. Remove the Chain: Remove the chain from the chainsaw.
2. Clean the Chain: Use a brush and solvent (such as kerosene or citrus degreaser) to remove sawdust and pitch from the chain.
3. Clean the Bar: Use a scraper or wire brush to remove sawdust and pitch from the bar. Pay special attention to the bar groove, where the chain rides.
4. Lubricate the Bar: Apply bar and chain oil to the bar groove.
5. Reinstall the Chain: Reinstall the chain on the chainsaw, making sure it is properly tensioned.

Key Concepts:

• Bar Groove: The groove in the chainsaw bar where the chain rides.
• Pitch: A sticky resin that can build up on the chain and bar.
• Bar and Chain Oil: A special oil designed to lubricate the chain and bar.

Materials and Costs:

My Experience: I once neglected to clean my chainsaw chain and bar for an extended period. The chain became caked with sawdust and pitch, and the bar groove was completely clogged. The chainsaw was cutting very poorly, and the chain was overheating. After cleaning the chain and bar, the chainsaw performed much better. I learned my lesson and now make it a habit to clean my chainsaw regularly.

Strategic Advantages:

• Reduced Friction: A clean chain and bar experience less friction, which translates to increased cutting efficiency and reduced wear and tear.
• Improved Lubrication: A clean bar groove allows for better lubrication of the chain, which further reduces friction and heat.
• Longer Chain Life: Regular cleaning helps to prevent the chain from rusting and corroding, extending its lifespan.

Pro Tip 5: Sharpen Your Chain Frequently

Don’t wait until your chain is completely dull to sharpen it. Sharpening your chain frequently will keep it cutting efficiently and reduce the amount of effort required to sharpen it.

Here’s how often you should sharpen your chain:

• After Every Tank of Fuel: This is a good rule of thumb for general use.
• When You Notice a Decrease in Cutting Performance: If your chainsaw is cutting slower or requiring more force, it’s time to sharpen the chain.
• If You Hit Dirt or Rocks: Hitting dirt or rocks can quickly dull your chain. Sharpen it immediately after.

Key Concepts:

• Preventative Maintenance: Sharpening your chain frequently is a form of preventative maintenance that can help to extend the life of your chain and chainsaw.

Timing Estimates:

• Sharpening Time: Sharpening a chain typically takes 10-15 minutes.

My Experience: I used to wait until my chain was completely dull before sharpening it. This made the sharpening process much more difficult and time-consuming. I also noticed that my chains were wearing out more quickly. Now, I sharpen my chain after every tank of fuel, and I’ve found that it’s much easier to keep my chain sharp and that my chains last longer.

Challenges Faced by Global DIYers and Small-Scale Logging Businesses:

• Access to Quality Tools: In some parts of the world, access to high-quality sharpening tools may be limited.
• Lack of Training: Many DIYers and small-scale logging businesses may not have received proper training on chainsaw maintenance and sharpening.
• Time Constraints: Sharpening a chainsaw can be time-consuming, which can be a challenge for those who are already busy.
• Cost of Tools: The cost of sharpening tools can be a barrier for some DIYers and small-scale logging businesses.

Solutions for Overcoming These Challenges:

• Invest in Quality Tools: Even if it means spending a little more money upfront, investing in quality sharpening tools will pay off in the long run.
• Seek Out Training: Look for workshops or online resources that can teach you how to properly sharpen a chainsaw.
• Make Time for Maintenance: Schedule regular maintenance for your chainsaw, including sharpening the chain.
• Share Tools and Resources: Consider sharing tools and resources with other DIYers or small-scale logging businesses.

Green Wood vs. Seasoned Wood:

• Green Wood: Wood that has been recently cut and still contains a high moisture content. Green wood is typically easier to split but harder to burn.
• Seasoned Wood: Wood that has been allowed to dry for a period of time, typically 6-12 months. Seasoned wood is harder to split but easier to burn.

Sharpening your chain is especially important when cutting seasoned wood, as it tends to be harder and more abrasive than green wood.

Felling Techniques:

• Hinge Wood: The portion of the tree that is left uncut during felling. The hinge wood controls the direction of the fall.
• Back Cut: The final cut made during felling. The back cut is made opposite the notch cut.
• Notch Cut: A wedge-shaped cut made on the side of the tree facing the direction of the fall.

A sharp chain is essential for making clean and accurate cuts during felling.

Debarking Logs:

• Draw Knife: A hand tool used to remove bark from logs.
• Debarking Machine: A machine used to remove bark from logs on a larger scale.

A sharp chain can be used to score the bark before debarking, making the process easier and more efficient.

Splitting Firewood:

• Axe: A hand tool used to split firewood.
• Hydraulic Splitter: A machine used to split firewood using hydraulic power.

A sharp chain can be used to cut firewood to the desired length before splitting.

Firewood Stacking:

• Rick: A stack of firewood that is 4 feet high, 8 feet long, and 4 feet wide.
• Cord: A stack of firewood that is 4 feet high, 8 feet long, and 4 feet wide.

Properly stacked firewood will dry more quickly and efficiently.

Drying Methods:

• Air Drying: The most common method of drying firewood. Air drying involves stacking the firewood in a well-ventilated area and allowing it to dry naturally.
• Kiln Drying: A method of drying firewood using a kiln. Kiln drying is faster than air drying but also more expensive.

The target moisture content for firewood is typically 20% or less.

Safety Considerations:

• Wear Safety Glasses: Always wear safety glasses when sharpening a chainsaw to protect your eyes from flying metal particles.
• Wear Gloves: Wear gloves to protect your hands from sharp teeth.
• Work in a Well-Ventilated Area: Work in a well-ventilated area to avoid breathing in metal dust.
• Be Careful: Be careful when handling sharp tools.

By following these safety precautions, you can minimize the risk of injury while sharpening your chainsaw.

Strategic Insights:

• Proactive Maintenance: Sharpening your chain regularly is a form of proactive maintenance that can help to prevent costly repairs and downtime.
• Improved Efficiency: A sharp chain will cut more efficiently, saving you time and energy.
• Increased Safety: A sharp chain is safer to use than a dull chain.

Next Steps:

1. Identify the Correct File Size: Consult your chainsaw’s owner’s manual or look for markings on the chain to determine the correct file size.
2. Gather Your Tools: Invest in quality sharpening tools, including round files, a flat file, a file guide, a depth gauge tool, a vise, and gloves.
3. Practice Your Technique: Practice sharpening your chain using the correct angles and techniques.
4. Clean Your Chain and Bar Regularly: Clean your chain and bar after each use to remove sawdust and pitch.
5. Sharpen Your Chain Frequently: Sharpen your chain after every tank of fuel or when you notice a decrease in cutting performance.

By following these steps, you can keep your chainsaw chain sharp and your chainsaw running smoothly.

In conclusion, mastering the art of chainsaw chain sharpening, particularly for models like the Stihl MS170, is a crucial skill for anyone involved in wood processing, logging, or firewood preparation. It’s not just about maintaining the chainsaw’s performance; it’s about ensuring safety, efficiency, and the longevity of your equipment. I’ve shared insights, practical tips, and even personal experiences to guide you through the process. Remember, investing in quality tools, understanding the correct angles, and maintaining the chain regularly are key elements. Now, armed with this knowledge, you’re ready to tackle your wood processing projects with confidence and precision.

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