What Size Weed Eater String for Dewalt? Quick Size Guide

Introduction

Choosing the right trimmer line can feel like a guessing game, especially when you own a Dewalt string trimmer and want to keep it running at peak performance. The question What Size Weed Eater String for Dewalt? comes up often because Dewalt offers several models, each with its own specifications for line diameter, shape, and material. Using the wrong size can lead to poor cutting efficiency, excessive line breakage, or even damage to the trimmer head. This guide walks you through everything you need to know to select, install, and maintain the perfect line for your Dewalt trimmer.

• Understanding Dewalt String Trimmer Models
• Standard String Diameter Options
• How to Determine the Correct Size for Your Model
• Common Dewalt Models and Recommended String Sizes
• Factors That Influence String Choice
• Installing New String: Step‑by‑Step Guide
• Tips for Extending String Life
• Common Mistakes to Avoid
• Troubleshooting String Feeding Issues
• Frequently Asked Questions
• Conclusion

Understanding Dewalt String Trimmer Models

Dewalt’s lineup includes both corded electric and battery‑powered string trimmers, each designed for different yard sizes and user preferences. The most common series are the 20V MAX XR line, the 60V MAX FLEXVOLT line, and the older 18V NiCad models. While the power source changes, the trimmer head geometry often stays consistent within a series, meaning the line diameter recommendation is usually shared across models that use the same head. Knowing your exact model number—found on the label near the motor housing—lets you cross‑reference the manufacturer’s specifications quickly.

Most Dewalt trimmers use a bump‑feed or automatic‑feed head that accepts a single line spool. Some newer models feature a dual‑line head for faster cutting, but the line diameter remains the same for both lines. If you have a model with a fixed‑line head (pre‑cut lengths), you still need to match the diameter, but you won’t worry about spool winding. Understanding whether your trimmer uses a spool or pre‑cut line helps you purchase the correct product format.

Standard String Diameter Options

Trimmer line is measured in inches or millimeters, and the most common diameters for Dewalt trimmers fall between 0.065 in (1.65 mm) and 0.095 in (2.41 mm). The three standard sizes you’ll encounter are:

• 0.065 in (1.65 mm) – Light‑duty line ideal for small yards, fine grass, and edging. It feeds easily but wears quickly on thick weeds.
• 0.080 in (2.03 mm) – The “all‑around” size recommended for most Dewalt 20V MAX and 60V MAX models. It balances cutting power with feed reliability.
• 0.095 in (2.41 mm) – Heavy‑duty line for dense brush, thick weeds, and commercial use. It requires a more robust motor and a head designed for the larger diameter.

Using a line thicker than the head’s maximum rating can cause the feed mechanism to jam, while a line that’s too thin may snap under load and reduce cutting efficiency. Always check the owner’s manual for the maximum approved diameter.

How to Determine the Correct Size for Your Model

1. Locate the model number. Find the label on the motor housing or battery compartment. It typically reads something like “DWST17000” or “DCST920P1”.
2. Consult the owner’s manual. The manual lists the recommended line diameter and whether the head accepts single or dual line. If you’ve lost the manual, Dewalt’s website has PDF versions searchable by model number.
3. Check the trimmer head markings. Many heads have a small imprint such as “0.080” or “2.0 mm” near the line exit port. This is a quick visual cue.
4. Match the line shape and material. Beyond diameter, decide between round, twisted, or serrated profiles based on the vegetation you’ll tackle (see the Factors section).
5. Purchase the correct spool or pre‑cut pack. Ensure the packaging states the exact diameter and that it’s compatible with Dewalt’s bump‑feed or automatic‑feed system.

Following these steps eliminates guesswork and ensures you’re not buying line that won’t feed or will over‑stress the motor.

Common Dewalt Models and Recommended String Sizes

The table below summarizes the most popular Dewalt string trimmers and the line diameter Dewalt officially recommends. Always verify with your specific manual, as regional variations can exist. (See Also:How To String A Kobalt 40v Weed Eater)

If your model isn’t listed, the same lookup process (model number → manual → head marking) will give you the answer.

Factors That Influence String Choice

Line Shape

Round line is the most common and works well for general grass trimming. Twisted or “serrated” line has a slight edge that slices through thicker stems more cleanly, reducing the chance of the line wrapping around tough weeds. Square or star‑shaped line offers the most aggressive cutting action but can increase vibration and wear on the head.

Line Material

Standard nylon copolymer is affordable and durable for typical lawn care. Co‑polymer blends with added abrasion resistance last longer on rocky or sandy terrain. Some premium lines incorporate a small percentage of titanium or ceramic particles to further extend life, which can be worthwhile for large properties.

Cutting Conditions

Dry, brittle grass cuts easily with thinner line, while wet, thick weeds demand a heavier gauge. If you frequently trim near fences, sidewalks, or flower beds, a smaller diameter reduces the risk of damaging hardscape. Conversely, open fields with heavy brush benefit from the 0.095 in option, provided your trimmer’s motor and head are rated for it.

Installing New String: Step‑by‑Step Guide

1. Power off and remove the battery. Safety first—ensure the trimmer cannot start accidentally.
2. Remove the spool cover. Most Dewalt heads have a latch or twist‑off cap. Press the release button and lift the cover.
3. Take out the empty spool. Pull the spool straight out; note the direction the line winds (usually indicated by an arrow on the spool).
4. Cut the new line to length. For a single‑line head, cut a piece about 10–12 ft (3–3.6 m). For dual‑line heads, cut two equal lengths.
5. Insert the line into the anchor hole. Feed one end into the small hole on the spool’s inner flange, leaving a short tail.
6. Wind the line evenly. Turn the spool in the direction of the arrow, keeping tension so the line lays flat without overlapping. Stop when the spool is about 80 % full to allow proper feeding.
7. Secure the line ends. Tuck the tails into the spool’s retaining slots or notches.
8. Reinstall the spool. Place the spool back into the head, aligning any guide tabs.
9. Replace the cover. Snap or twist the cover back until it clicks.
10. Reattach the battery and test. Tap the head on the ground to advance line; it should feed smoothly.

If the line fails to feed, double‑check that you wound in the correct direction and that the line isn’t crossed over itself.

Tips for Extending String Life

• Keep the trimmer head clean; debris buildup increases friction and causes premature wear.
• Use the correct line shape for the job—twisted line lasts longer on thick stems than round line.
• Avoid letting the line hit hard surfaces like concrete or metal edging; this creates micro‑fractures.
• Store spare line in a cool, dry place; UV exposure degrades nylon over time.
• Periodically lubricate the feed mechanism with a light silicone spray (if the manual permits) to keep the bump‑feed action smooth.
• Trim at a consistent speed; revving the motor excessively stretches the line and leads to breakage.

Common Mistakes to Avoid

• Using a diameter larger than the head rating. This jams the feed and can overheat the motor.
• Mixing line diameters on a dual‑line head. Uneven line lengths cause vibration and uneven cutting.
• Over‑filling the spool. Too much line prevents the bump‑feed from releasing new line.
• Ignoring the winding direction. Winding opposite the arrow makes the line feed backward or not at all.
• Buying generic “universal” spools without verifying compatibility. Some universal spools have slightly different hub dimensions that cause wobble.

Troubleshooting String Feeding Issues

If the line won’t advance, first confirm the spool isn’t over‑filled and that the line is wound in the correct direction. Next, inspect the feed eyelet for burrs or debris; a small file can smooth rough edges. On automatic‑feed heads, the internal spring may weaken over time—replacing the spring assembly restores reliable feeding. For bump‑feed heads, ensure the bump knob moves freely; a stuck knob often means dirt has entered the mechanism. Cleaning the head with compressed air and a soft brush usually resolves the problem.

Frequently Asked Questions

What Size Weed Eater String for Dewalt 20V Trimmers?

Most Dewalt 20V MAX XR trimmers are designed for 0.080 in (2.03 mm) line. Check your specific model’s manual, but 0.080 in is the standard recommendation for both single‑ and dual‑line heads in this voltage class. (See Also:How To Reload Craftsman Weed Eater)

Can I Use 0.095‑Inch Line on a 20V Model?

Generally, no. The 20V motors and bump‑feed heads are calibrated for a maximum of 0.080 in. Using 0.095 in can cause the feed to jam and may overheat the motor, voiding the warranty.

How Often Should I Replace the Trimmer Line?

Replace the line when you notice frequent breakage, reduced cutting width, or when the line length falls below the minimum feed length (usually about 2 in). For average residential use, a fresh spool lasts several months.

Is Twisted Line Better Than Round Line?

Twisted or serrated line cuts thicker stems more cleanly and can last longer in heavy brush, but it may increase vibration. For typical lawn grass, round line is perfectly adequate and often feeds more smoothly.

Where Can I Buy Genuine Dewalt Trimmer Line?

Authorized Dewalt dealers, major home‑improvement retailers, and the official Dewalt website sell OEM line spools. Genuine line guarantees the correct diameter, hub fit, and material quality. (See Also:How To Thread A Homelite Weed Eater)

Conclusion

Selecting the right trimmer line for your Dewalt string trimmer comes down to knowing your model, reading the manufacturer’s specifications, and matching the line diameter, shape, and material to the vegetation you’ll cut. The most common answer to What Size Weed Eater String for Dewalt? is 0.080 in for the majority of 20V MAX models, while 60V FLEXVOLT units often call for 0.095 in and older 18V units work best with 0.065 in. By following the step‑by‑step installation guide, avoiding common mistakes, and applying the maintenance tips outlined above, you’ll keep your trimmer feeding smoothly and cutting efficiently all season long. Proper line selection not only improves performance but also protects your investment in the tool itself.