What Size String Does Stihl Weed Eater Use? Model Specs

Introduction

One of the most common questions among STIHL weed eater owners and potential buyers is, “What size string does STIHL weed eater use?” The answer isn\’t always straightforward because STIHL manufactures a wide variety of string trimmers, each with different specifications. Whether you are replacing worn-out line, upgrading to a thicker gauge for heavy-duty work, or trying to determine compatibility before purchasing accessories, understanding the correct string size for your specific model is essential for optimal performance and longevity of your tool.

This article will walk you through everything you need to know about STIHL weed eater string sizes, including how to identify the correct size for your model, common sizes used across different series, and tips for choosing the right line for your trimming needs. We will also cover how to replace the string properly and where to find the information you need in your owner\’s manual or on the tool itself.

• Table of Contents
• Understanding String Sizes
• How to Find Your Model Number
• Common String Sizes by STIHL Series
• How to Measure Your Current String
• Step-by-Step String Replacement Guide
• String Material Types Explained
• Comparison Table of STIHL Models and String Sizes
• Tips for Choosing the Right String
• Common Mistakes and How to Avoid Them
• When to Replace Your Trimmer Line
• Troubleshooting String Issues
• Accessories and Additional Tools
• Frequently Asked Questions
• Conclusion

Understanding String Sizes

STIHL weed eater string sizes are typically measured by diameter, which is expressed in inches or millimeters. The diameter of the string affects how well it cuts through vegetation and how durable it is. Thicker strings are more aggressive and better suited for tough, woody plants, while thinner strings are ideal for light trimming around delicate landscaping.

String sizes commonly range from 0.063 inches (1.6 mm) to 0.130 inches (3.3 mm) in diameter. The size you choose depends on several factors, including the power of your trimmer, the type of vegetation you are clearing, and the specific model of your STIHL tool. Using a string that is too thick for your trimmer can overload the engine or motor, while using one that is too thin may not provide adequate cutting power.

Beyond diameter, string size can also refer to the length of line that fits on the spool or in the trimmer head. Most STIHL trimmers use a fixed amount of line that is pre-loaded on the spool, but some models allow you to adjust the amount of line extended during operation. Understanding both the diameter and length specifications is important for maintaining peak performance.

How to Find Your Model Number

Before determining what size string your STIHL weed eater uses, you need to identify your exact model. STIHL places model numbers in several locations depending on the type of trimmer you own. For handheld string trimmers, the model number is usually found on a metal plate or sticker located on the engine housing or the trimmer head assembly. On backpack-style trimmers, check the frame or the engine cover.

You can also find your model number in your owner\’s manual, which is available for download on the official STIHL website. If you do not have your manual on hand, visit the STIHL website and use their model lookup tool by entering your serial number or browsing their product catalog. Knowing your model number allows you to access detailed specifications, including the recommended string size, line type, and spool capacity.

Another reliable method is to remove the trimmer head and inspect the spool. Many spools have the string size printed directly on them. If the original spool is still intact, this is often the quickest way to determine the correct replacement string. However, if the spool has been replaced or modified, you will need to rely on your model number to ensure accuracy.

Common String Sizes by STIHL Series

STIHL organizes its string trimmers into different series based on power source and intended use. Each series tends to use a specific range of string sizes. Here is a breakdown of the most common string sizes associated with popular STIHL trimmer series:

FS Series (Gas-Powered)

The FS series includes STIHL\’s full line of gas-powered string trimmers, ranging from lightweight residential models to heavy-duty commercial units. Residential models in the FS 38 to FS 55 range typically use string sizes between 0.080 inches (2.0 mm) and 0.095 inches (2.4 mm). Mid-range commercial models like the FS 70 and FS 80 often use 0.095 inches (2.4 mm) to 0.105 inches (2.7 mm). Heavy-duty models such as the FS 90, FS 91, and FS 120 series can accommodate strings up to 0.130 inches (3.3 mm) in diameter.

FSE Series (Electric-Powered)

The FSE series consists of electric trimmers designed for lighter-duty tasks around the home. These models typically use thinner strings, usually between 0.063 inches (1.6 mm) and 0.080 inches (2.0 mm). The compact design and lower power output of electric trimmers mean they do not require the thicker lines used in gas-powered models. Popular models like the FSE 60 and FSE 71 often use 0.075 inches (1.9 mm) or 0.080 inches (2.0 mm) line.

HTA Series (Battery-Powered)

The HTA series includes STIHL\’s cordless string trimmers powered by their lithium-ion battery system. These trimmers are designed for medium-duty residential use and typically use string sizes between 0.080 inches (2.0 mm) and 0.095 inches (2.4 mm). Models like the HTA 50 and HTA 65 are popular choices for homeowners who want the convenience of cordless operation without sacrificing too much cutting power.

HLA Series (Battery-Powered Hedge Trimmers)

While not traditional string trimmers, the HLA series includes battery-powered hedge trimmers that sometimes use similar line systems. These models generally use smaller diameter strings, typically around 0.063 inches (1.6 mm) to 0.080 inches (2.0 mm), due to their specialized cutting applications.

How to Measure Your Current String

If you do not have access to your model number or owner\’s manual, you can measure your current string to determine the correct replacement size. Here is how to do it:

1. Turn off and disconnect your trimmer. Always ensure the tool is completely powered off and the spark plug wire is disconnected before handling the trimmer head.
2. Remove the trimmer head. Most STIHL trimmer heads can be removed by pressing the release button and twisting counterclockwise. Refer to your manual if you encounter resistance.
3. Extract the spool. Once the head is removed, carefully pull out the spool that holds the cutting line. Be cautious as the spring inside may be under tension.
4. Measure the string diameter. Use a ruler or caliper to measure the thickness of the string. If you have a piece of the old string, measure it directly. If the string is still on the spool, measure the thickness of the line as it comes off the spool.
5. Check for printed specifications. Many spools have the string size printed on them. Look for numbers like 0.080 or 2.0 mm, which indicate the diameter.

Once you have measured the diameter, you can purchase replacement string that matches this specification. It is important to note that even if you measure your current string, you should verify that the size is appropriate for your model by consulting your manual or STIHL\’s official specifications.

Step-by-Step String Replacement Guide

Replacing the string on your STIHL weed eater is a straightforward process, but doing it correctly ensures optimal performance and prevents damage to your tool. Follow these steps to replace your trimmer line:

1. Safety first. Disconnect the spark plug wire on gas models or remove the battery on cordless models. Wear safety glasses and work gloves to protect yourself from debris.
2. Remove the trimmer head. Press the release button on the trimmer head and rotate it counterclockwise to detach it from the drive shaft. Place the head on a clean, flat surface.
3. Take out the old spool. Carefully remove the spool from the trimmer head. Note how the old string is wound so you can replicate the pattern with the new line.
4. Clean the head assembly. Use a soft brush or cloth to remove any dirt, grass clippings, or debris from the inside of the trimmer head and the spool chamber.
5. Prepare the new spool or string. If you are using a pre-wound spool, simply insert it into the head. If you are rewinding string manually, cut a length of new line that matches your model\’s specifications. Thread one end through the small hole in the center of the spool.
6. Wind the string correctly. Wind the string in the direction indicated by the arrows on the spool. Keep the windings tight and even to prevent tangling during operation. Leave about 6 inches of loose string extending from the spool.
7. Reinstall the spool. Place the spool back into the trimmer head, ensuring it sits flush and the loose end of the string passes through the exit hole in the head.
8. Attach the trimmer head. Align the head with the drive shaft and twist it clockwise until it clicks into place. Reconnect the spark plug wire or reinsert the battery.
9. Test the line feed. Pull the trigger to advance the line. The string should extend smoothly and retract properly when released.

Following these steps carefully will help you avoid common issues such as line tangles, improper feeding, and premature wear. If the line does not feed correctly after replacement, double-check that the spool is seated properly and the string is wound in the correct direction.

String Material Types Explained

In addition to diameter, the material composition of your trimmer line plays a significant role in its performance. STIHL offers several types of string materials, each suited for different trimming tasks and preferences:

Nylon String

Nylon is the most common material used in STIHL trimmer lines. It is durable, resistant to abrasion, and maintains flexibility in various weather conditions. Standard nylon lines are suitable for general-purpose trimming of grass and light weeds. They are available in different diameters to match your trimmer\’s specifications.

Reinforced String

Some STIHL lines incorporate reinforcing materials such as fiberglass or polyester fibers embedded within the nylon. These reinforced lines are more durable and better suited for cutting through thicker vegetation, including small branches and woody stems. They are often used in commercial-grade trimmers where heavy-duty performance is required.

Biodegradable String

For environmentally conscious users, STIHL offers biodegradable trimmer lines made from plant-based materials. These lines break down more quickly in the environment compared to traditional nylon. While they may not last as long as standard lines, they are an excellent choice for users who prioritize sustainability and frequently trim in areas where line fragments might end up in compost or garden beds.

Specialty Shapes

Beyond material, STIHL also produces strings with unique cross-sectional shapes, such as star-shaped or twisted profiles. These designs increase the cutting surface area and can improve performance in specific applications. Star-shaped lines are particularly effective for clearing thick grass and weeds, while twisted lines offer enhanced durability and reduced wind resistance.

Comparison Table of STIHL Models and String Sizes

This table provides a general overview of string sizes for some of the most popular STIHL trimmer models. Always refer to your specific model\’s owner manual or STIHL\’s official documentation for the most accurate and up-to-date information.

Tips for Choosing the Right String

Selecting the correct string size and type for your STIHL weed eater can significantly impact its performance and longevity. Here are some practical tips to help you make the best choice:

• Match the diameter to your trimmer\’s power. More powerful trimmers can handle thicker strings, while less powerful models require thinner lines to avoid strain on the engine or motor.
• Consider your trimming environment. If you regularly trim around hard surfaces like concrete or stone, choose a more abrasion-resistant line. For softer vegetation, standard nylon may suffice.
• Choose the right material for the job. Reinforced lines are better for heavy-duty tasks, while biodegradable options are ideal for environmentally sensitive areas.
• Check the manufacturer\’s recommendations. STIHL specifies the optimal string size for each model to ensure safe and effective operation. Deviating from these recommendations can lead to poor performance or damage.
• Keep spare spools on hand. Having pre-wound spools in the correct size for your model makes replacement quick and easy, reducing downtime during yard work.
• Pay attention to line shape. Specialty shapes like star or twisted profiles can enhance cutting efficiency for specific tasks, so consider your typical trimming challenges when selecting a line.

Common Mistakes and How to Avoid Them

Even experienced STIHL users can make errors when selecting or replacing trimmer line. Here are some of the most common mistakes and how to prevent them:

Using the Wrong Diameter

Installing a string that is too thick for your trimmer can overload the engine or motor, leading to poor performance, excessive wear, and potential damage. Conversely, using a string that is too thin may not provide adequate cutting power and can break frequently. Always verify the correct diameter for your specific model before purchasing replacement line.

Improper Winding Technique

Winding the string too loosely or in the wrong direction can cause tangles and uneven line feed. Follow the arrows on the spool and keep the windings tight and even. If the line tangles frequently after replacement, disassemble the head and rewind the string carefully.

Ignoring Line Material

Not all trimmer lines are created equal. Using a standard nylon line for heavy-duty tasks like cutting through thick brush or small branches can result in frequent line breaks and poor performance. Choose a reinforced or specialty line that matches your trimming needs.

Neglecting Regular Maintenance

Failing to replace worn or frayed string can reduce cutting efficiency and put additional strain on your trimmer. Make it a habit to inspect the line before each use and replace it when it becomes damaged or excessively short.

When to Replace Your Trimmer Line

Knowing when to replace your trimmer line is just as important as knowing what size to use. Here are the key indicators that it is time for a new line:

• Fraying or splitting. If the string appears frayed, split, or has visible damage along its length, it is time to replace it immediately.
• Excessive shortening. If the line has become too short to extend properly through the trimmer head, it will not feed correctly and must be replaced.
• Poor cutting performance. A dull or worn line that fails to cut through vegetation effectively indicates that the string needs to be refreshed.
• Frequent tangling. Persistent line tangles or knots, especially after a recent replacement, can signal improper winding or the use of incompatible string.
• Seasonal use. After extended storage or at the beginning of each trimming season, inspect the line and replace it if necessary to ensure optimal performance.

Regular inspection and timely replacement of your trimmer line will keep your STIHL tool running smoothly and extend its overall lifespan.

Troubleshooting String Issues

If you encounter problems with your trimmer line after replacement, here are some common issues and their solutions:

Line Not Feeding Properly

If the line does not extend when you pull the trigger, check that the spool is seated correctly and the string is threaded through the exit hole. Ensure the line is wound in the proper direction and that there are no kinks or tangles inside the head.

Line Breaking Frequently

Frequent line breakage can be caused by using a string that is too thin for your trimmer or by hitting hard objects like rocks or concrete. Switch to a thicker or reinforced line and take care to avoid striking solid surfaces during trimming.

Excessive Vibration

If your trimmer vibrates excessively after replacing the line, the spool may not be seated properly or the windings may be uneven. Disassemble the head, check the spool alignment, and rewind the string evenly.

Automatic Feed Not Working

Some STIHL trimmers feature automatic line feed mechanisms that advance the string when it becomes too short. If this function stops working, clean the feed mechanism and ensure the spool is installed correctly. Refer to your manual for specific troubleshooting steps for your model.

Accessories and Additional Tools

STIHL offers a range of accessories and replacement parts designed to complement their string trimmers. These include pre-wound spools in various sizes, replacement trimmer heads, and specialized cutting tools for different vegetation types. Investing in genuine STIHL accessories ensures compatibility and maintains the quality and performance standards you expect from your tool.

In addition to standard replacement string, STIHL also produces cutting blades and saws that can be attached to certain trimmer models for more demanding tasks. These attachments typically require a different head assembly and may not be compatible with all models. Always check your trimmer\’s specifications before purchasing additional accessories.

Frequently Asked Questions

What Size String Does STIHL Weed Eater Use?

The string size for a STIHL weed eater depends on the specific model. Common diameters range from 0.063 inches (1.6 mm) for lightweight electric models to 0.130 inches (3.3 mm) for heavy-duty gas-powered units. Always consult your owner\’s manual or STIHL\’s official specifications for the exact size recommended for your model.

Can I Use Any Size String in My STIHL Trimmer?

No, using the wrong string size can damage your trimmer or reduce its performance. STIHL designs each trimmer to work optimally with a specific string diameter. Installing a string that is too thick can overload the engine or motor, while one that is too thin may not cut effectively and can break frequently.

How Do I Know What Size String My STIHL Uses?

You can determine the correct string size by checking your owner\’s manual, visiting the STIHL website with your model number, or inspecting the spool for printed specifications. Measuring the existing string with a ruler or caliper is also an option, but confirming with official sources is recommended.

What Is the Most Common String Size for STIHL Trimmers?

The most common string sizes for STIHL trimmers fall between 0.080 inches (2.0 mm) and 0.095 inches (2.4 mm). These sizes are widely used across both gas and electric models for general-purpose trimming of grass and light weeds.

Should I Use Thicker String for Heavier Grass?

While thicker string is more durable and better suited for tough vegetation, you should only use a size that is compatible with your trimmer model. Using a string that is too thick for your tool can cause strain on the engine or motor and lead to performance issues.

How Often Should I Replace My Trimmer Line?

Replace your trimmer line whenever it becomes frayed, split, or too short to function properly. For regular users, this may mean replacing the line several times per season. At the beginning of each trimming season, inspect the line and replace it if necessary to ensure optimal performance.

Are Biodegradable Strings Compatible with All STIHL Models?

Biodegradable strings are available in various diameters and are compatible with most STIHL trimmer models. However, they may not be as durable as traditional nylon lines and are best suited for light to medium-duty trimming tasks. Check your model\’s specifications to confirm compatibility.

Can I Replace the String Myself or Do I Need a Professional?

Replacing the string on a STIHL weed eater is a straightforward process that most users can perform themselves. With the correct tools and a bit of patience, you can remove the old string and install a new one by following the steps outlined in your owner\’s manual or in this guide.

Conclusion

Determining what size string your STIHL weed eater uses is a critical step in maintaining your tool\’s performance and longevity. By identifying your model number, consulting official specifications, and understanding the relationship between string size, material, and trimming tasks, you can make informed decisions that enhance your trimming experience. Whether you are replacing line on a gas-powered FS series trimmer or a cordless HTA model, using the correct string size ensures efficient cutting, reduces wear on your tool, and minimizes the need for frequent repairs. Regular maintenance, proper winding techniques, and timely replacement of worn line will keep your STIHL weed eater operating at its best season after season. Remember to always prioritize safety when handling your trimmer and consult your owner\’s manual for model-specific guidance. With the right string and a little attention to detail, your STIHL tool will continue to deliver reliable performance for years to come.