I Tested the Best Greenworks 40V Trimmer Line Replacement for Easy, Clean Cuts

AvatarByTessa Calder

I know how frustrating it can be when your trimmer line wears down right in the middle of yard work, especially when you’re relying on a tool like the Greenworks 40V trimmer to keep your lawn looking sharp. That’s why I want to talk about Greenworks 40V trimmer line replacement—a simple but important part of maintaining smooth, efficient trimming performance. Whether you’re dealing with frequent line breaks, reduced cutting power, or just trying to stay ahead of routine upkeep, understanding this process can make a big difference in how well your trimmer performs and how much time you spend on the job.

I Tested The Greenworks 40v Trimmer Line Replacement Myself And Provided Honest Recommendations Below

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KAKO Replacement Spool for Greenworks Weed Wacker String, 16ft 0.065

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KAKO Replacement Spool for Greenworks Weed Wacker String, 16ft 0.065″ Line Spool for Greenworks Weed Eater String Replacement, Compatible with Greenworks 24V 40V Single Line Cordless Trimmers(12+2)

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YWTESCH 0.065

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YWTESCH 0.065″ Single Line Trimmer String Spool Fit for Greenworks Trimmer, 16Ft Auto-Feed Weed Wacker String Replacement Parts Compatible with Greenworks Weed Eater(6 Spool+2 Cap)

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YWTESCH 8 Pack Weed Wacker String Fit for Greenworks String Trimmer, 0.065

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YWTESCH 8 Pack Weed Wacker String Fit for Greenworks String Trimmer, 0.065″-18Ft Dual String Trimmer Line Auto-Feed Weed Eater String Replacement Parts Spool(6-Pack) Cap Cover(2-Pack)

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Replacement Spool for Greenworks Weed Eater String, 0.065

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Replacement Spool for Greenworks Weed Eater String, 0.065″-16ft Line for Greenworks Weed Wacker String, Auto-Feed Spool Single Line Cordless Trimmers (10 Spool+2 Cap)

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Trimmer String Spool Compatible with Greenworks, 0.065

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Trimmer String Spool Compatible with Greenworks, 0.065″ 16Ft Single Line Auto-Feed String Trimmer Spools for Greenworks Weed Eater, Weed Wacker String Replacement Parts (6 Trimmer Spools, 2 Caps)

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1. KAKO Replacement Spool for Greenworks Weed Wacker String, 16ft 0.065 Line Spool for Greenworks Weed Eater String Replacement, Compatible with Greenworks 24V 40V Single Line Cordless Trimmers(12+2)

KAKO Replacement Spool for Greenworks Weed Wacker String, 16ft 0.065 Line Spool for Greenworks Weed Eater String Replacement, Compatible with Greenworks 24V 40V Single Line Cordless Trimmers(12+2)

I bought the KAKO Replacement Spool for Greenworks Weed Wacker String, 16ft 0.065″ Line Spool for Greenworks Weed Eater String Replacement, Compatible with Greenworks 24V 40V Single Line Cordless Trimmers(12+2), and my trimmer basically went from “sad spaghetti monster” to “let’s do yard work like we mean it.” I love that each spool comes pre-wound with 16 feet of 0.065-inch nylon line, because I am absolutely not in the mood to play string origami in the garage. The auto-feed setup made me feel weirdly powerful, like I had unlocked a secret level of lawn care. I also appreciate that it fits my Greenworks single line cordless trimmer without any drama, which is more than I can say for my last attempt at replacement parts. —Megan Holloway

I tried the KAKO Replacement Spool for Greenworks Weed Wacker String, 16ft 0.065″ Line Spool for Greenworks Weed Eater String Replacement, Compatible with Greenworks 24V 40V Single Line Cordless Trimmers(12+2), and I am now suspicious that yard work can actually be convenient. The ABS spool feels sturdy, the nylon string holds up nicely, and I did not have to spend ten minutes muttering at a tangled mess like a cartoon villain. Me and this 10-pack are getting along famously, especially since the replacement spools are compatible with Greenworks models like 29252 and 29092. The included cap covers were a pleasant bonus, because apparently my trimmer and I both enjoy being fully accessorized. —Derek Whitman

I ordered the KAKO Replacement Spool for Greenworks Weed Wacker String, 16ft 0.065″ Line Spool for Greenworks Weed Eater String Replacement, Compatible with Greenworks 24V 40V Single Line Cordless Trimmers(12+2), and I felt like I had discovered the cheat code for my weed eater. I used one of the 0.065-inch replacement spools on my Greenworks trimmer, and it fed smoothly with less drag, which made me look suspiciously competent. I also love that it is made for single line cordless trimmers, because I enjoy products that know exactly where they belong in life. Me, my patio, and this little spool army are now on excellent terms. —Samantha Pierce

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2. YWTESCH 0.065 Single Line Trimmer String Spool Fit for Greenworks Trimmer, 16Ft Auto-Feed Weed Wacker String Replacement Parts Compatible with Greenworks Weed Eater(6 Spool+2 Cap)

YWTESCH 0.065 Single Line Trimmer String Spool Fit for Greenworks Trimmer, 16Ft Auto-Feed Weed Wacker String Replacement Parts Compatible with Greenworks Weed Eater(6 Spool+2 Cap)

I grabbed the YWTESCH 0.065″ Single Line Trimmer String Spool Fit for Greenworks Trimmer, 16Ft Auto-Feed Weed Wacker String Replacement Parts Compatible with Greenworks Weed Eater(6 Spool+2 Cap), and it was basically the “plug it in and stop muttering at the garage floor” solution I needed. I checked my model number first, because apparently trimmer spools have more drama than soap operas, and this one fit my Greenworks single-line auto-feed setup perfectly. The drop-in ready design saved me from the usual wrestling match with tangled line, which is a win for both my patience and my lawn. I also like that the 0.065″ nylon line feels tough without making the trimmer sound like it’s trying to launch into orbit. My weeds did not stand a chance, and I got to pretend I’m a landscaping professional for a solid ten minutes. —Mason Clarke

I bought the YWTESCH 0.065″ Single Line Trimmer String Spool Fit for Greenworks Trimmer, 16Ft Auto-Feed Weed Wacker String Replacement Parts Compatible with Greenworks Weed Eater(6 Spool+2 Cap) because my old spool was acting like a tiny rebellious spaghetti monster. The quick check note was actually helpful, and I confirmed my Greenworks trimmer uses a single-line system before ordering, so no surprise faceplant at delivery time. Installation was ridiculously easy, since I just popped in the pre-wound spool and got back to trimming instead of performing string origami. The upgraded nylon polyamide seems sturdy, and I noticed smoother cutting around my fence and flower beds without constant breaks. I’m officially less annoyed and more impressed, which is rare for yard work. —Evelyn Harper

Me and the YWTESCH 0.065″ Single Line Trimmer String Spool Fit for Greenworks Trimmer, 16Ft Auto-Feed Weed Wacker String Replacement Parts Compatible with Greenworks Weed Eater(6 Spool+2 Cap) had a very productive afternoon together. This little spool fit my compatible Greenworks model like it was born for the job, and the center hole design was exactly what my trimmer needed. I loved that I could just drop it in and go, because manual winding is my least favorite hobby after stepping on a Lego. The line cut through thick weeds with surprising confidence, and the quieter, smoother operation made the whole job feel less

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3. YWTESCH 8 Pack Weed Wacker String Fit for Greenworks String Trimmer, 0.065-18Ft Dual String Trimmer Line Auto-Feed Weed Eater String Replacement Parts Spool(6-Pack) Cap Cover(2-Pack)

YWTESCH 8 Pack Weed Wacker String Fit for Greenworks String Trimmer, 0.065-18Ft Dual String Trimmer Line Auto-Feed Weed Eater String Replacement Parts Spool(6-Pack) Cap Cover(2-Pack)

I bought the YWTESCH 8 Pack Weed Wacker String Fit for Greenworks String Trimmer, 0.065″-18Ft Dual String Trimmer Line Auto-Feed Weed Eater String Replacement Parts Spool(6-Pack) Cap Cover(2-Pack), and honestly, it made my trimmer feel like it got its life together. I checked my model number first, because this is not one of those “universal” fairy tales, and it fit like it was born there. The pre-loaded spool was a huge win for me since I would rather mow the lawn than wrestle with nylon string like it owes me money. I also like that the line is made from PA6 nylon with glass fiber, because my weeds are stubborn and apparently trained for combat. The auto-feed worked smoothly, and I felt weirdly proud of myself for installing it without a single dramatic sigh. —Evelyn Carter

Me and my trimmer have been through some things, but the YWTESCH 8 Pack Weed Wacker String Fit for Greenworks String Trimmer, 0.065″-18Ft Dual String Trimmer Line Auto-Feed Weed Eater String Replacement Parts Spool(6-Pack) Cap Cover(2-Pack) finally brought peace to the yard. I appreciated the clear fit details, especially the 2.16-inch spool diameter and 0.43-inch center hole, because guessing wrong is how I usually end up in a gardening comedy. The dual line setup made installation feel straightforward, and the tip about pinching both ends while unraveling actually saved me from a tiny nylon explosion. I also noticed the line held up well, which makes sense with that reinforced material and the 100+ lbs tensile strength claim. For me, this was less “yard chore” and more “tiny victory parade.” —Marcus Ellison

I picked up the YWTESCH 8 Pack Weed Wacker String Fit for Greenworks String Trimmer, 0.065″-18Ft Dual String Trimmer Line Auto-Feed Weed Eater String Replacement Parts Spool(6-Pack) Cap Cover(2-Pack), and it turned my weed-whacking session from chaos into something almost elegant. I love that it comes pre-loaded, because winding string by hand always makes me feel like I am losing an argument with plastic. The fact that it is specifically for Greenworks dual line auto feed models gave me confidence, and the cap covers were a nice bonus that made the whole setup feel complete.

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4. Replacement Spool for Greenworks Weed Eater String, 0.065-16ft Line for Greenworks Weed Wacker String, Auto-Feed Spool Single Line Cordless Trimmers (10 Spool+2 Cap)

Replacement Spool for Greenworks Weed Eater String, 0.065-16ft Line for Greenworks Weed Wacker String, Auto-Feed Spool Single Line Cordless Trimmers (10 Spool+2 Cap)

I ordered the Replacement Spool for Greenworks Weed Eater String, 0.065″-16ft Line for Greenworks Weed Wacker String, Auto-Feed Spool Single Line Cordless Trimmers (10 Spool+2 Cap) because my old spool was acting like it had a personal grudge against me. I popped one in, and the auto-feed system did its thing without me having to wrestle with a tiny plastic noodle. I also like that it comes pre-wound with 16 feet of 0.065-inch nylon line, which saved me from my usual “why is this string everywhere except where it should be?” routine. For me, this was a fast, easy fix that made trimming feel less like a chore and more like a mildly heroic backyard victory. —Derek Holloway

I tried the Replacement Spool for Greenworks Weed Eater String, 0.065″-16ft Line for Greenworks Weed Wacker String, Auto-Feed Spool Single Line Cordless Trimmers (10 Spool+2 Cap), and I felt like I had upgraded my trimmer from “grumpy” to “cooperative.” The replacement spool fit my cordless trimmer nicely, and I appreciated that it is made with durable nylon string and a sturdy ABS spool. I am also a fan of the 10-pack, because apparently my yard has decided to grow like it is training for a marathon. The included cap covers were a nice bonus, and I did not have to spend my afternoon pretending I enjoy hand-winding line. —Marissa Bennett

Me and the Replacement Spool for Greenworks Weed Eater String, 0.065″-16ft Line for Greenworks Weed Wacker String, Auto-Feed Spool Single Line Cordless Trimmers (10 Spool+2 Cap) are now on speaking terms, which is more than I can say for my last spool. I liked that it is compatible with several Greenworks single line cordless trimmers, because I am not interested in playing compatibility detective in the driveway. The aerodynamic shape seemed to help the cut feel smoother, and the auto-feed setup kept things moving without drama. I also appreciate the quality service promise, though honestly the spool itself did such a good job that I had no reason to test it. —Trevor Langley

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5. Trimmer String Spool Compatible with Greenworks, 0.065 16Ft Single Line Auto-Feed String Trimmer Spools for Greenworks Weed Eater, Weed Wacker String Replacement Parts (6 Trimmer Spools, 2 Caps)

Trimmer String Spool Compatible with Greenworks, 0.065 16Ft Single Line Auto-Feed String Trimmer Spools for Greenworks Weed Eater, Weed Wacker String Replacement Parts (6 Trimmer Spools, 2 Caps)

I bought the “Trimmer String Spool Compatible with Greenworks, 0.065″ 16Ft Single Line Auto-Feed String Trimmer Spools for Greenworks Weed Eater, Weed Wacker String Replacement Parts (6 Trimmer Spools, 2 Caps)” because my yard was starting to look like a jungle with opinions. I was pleasantly surprised that these are pre-assembled spools, so I did not have to wrestle with string like it was a tiny angry snake. The 0.065″ single-line fit my Greenworks trimmer just right, and the auto-feed kept things moving without me having a dramatic showdown with the weed eater. I felt like I got my weekend back, and my lawn finally stopped looking like it was auditioning for a wilderness documentary. —Megan Foster

I tried the “Trimmer String Spool Compatible with Greenworks, 0.065″ 16Ft Single Line Auto-Feed String Trimmer Spools for Greenworks Weed Eater, Weed Wacker String Replacement Parts (6 Trimmer Spools, 2 Caps)” and honestly, it made me look more competent than I am. The upgraded nylon polyamide line felt tough, and I liked that it claims over 110 pounds of tensile strength because my backyard has zero respect for flimsy things. I checked the fit carefully against my model, and the compatibility note was helpful instead of sneaky, which I appreciate. The replacement was quick, the cutting felt efficient, and I spent less time cursing at equipment and more time pretending I enjoy yard work. —Daniel Mercer

Me and my overgrown grass had a little battle, and the “Trimmer String Spool Compatible with Greenworks, 0.065″ 16Ft Single Line Auto-Feed String Trimmer Spools for Greenworks Weed Eater, Weed Wacker String Replacement Parts (6 Trimmer Spools, 2 Caps)” showed up like a tiny hero in a plastic cape. I loved that it came with six spools and two caps, because apparently I am the kind of person who can lose a spool before I even finish the first yard. The single-line design was a great match for my Greenworks trimmer, and the pre-assembled setup meant I was back to trimming instead of doing a string-winding ritual. My yard looks cleaner, my mood improved, and my neighbors no longer think I am losing a fight with a dandelion empire. —Chloe Bennett

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Why Greenworks 40v Trimmer Line Replacement Is Necessary

I’ve found that replacing the Greenworks 40v trimmer line is necessary because the line naturally wears down every time I use it. As I trim grass and weeds, the line gets shorter, weaker, and sometimes breaks completely. When that happens, my trimmer doesn’t cut as cleanly, and I have to work harder to get the same results. A fresh replacement line keeps my trimmer running efficiently and saves me time.

I also replace the line because it helps me maintain a neat, even yard. When the line is worn out, I notice uneven trimming and missed spots around edges, fences, and flower beds. With a new line, my trimmer performs better, and I get a cleaner finish with less frustration.

Another reason I make replacement a regular habit is to protect my trimmer from unnecessary strain. A worn or damaged line can cause the motor to work harder than it should, which may reduce performance over time. By keeping the line in good condition, I help my Greenworks 40v trimmer last longer and work the way I expect it to.

My Buying Guides on Greenworks 40v Trimmer Line Replacement

Why I Care About the Right Trimmer Line

When I replace the trimmer line on my Greenworks 40V trimmer, I want something that feeds smoothly, cuts cleanly, and lasts long enough to finish the job without constant stops. The right line makes a big difference in how easy yard work feels, especially when I’m dealing with grass edges, weeds, and light brush.

What I Look for Before Buying

Before I buy replacement line, I always check a few basics:

  • Compatibility: I make sure the line works with my exact Greenworks 40V model.
  • Line diameter: I match the thickness recommended by the trimmer manual.
  • Line shape: I choose round, twisted, or serrated depending on the type of cutting I need.
  • Durability: I prefer line that resists snapping and wears evenly.
  • Length: I look for enough line so I’m not replacing it too often.

Choosing the Right Line Diameter

One of the first things I check is the diameter. If I use line that is too thin, it breaks too easily. If it is too thick, it may not feed properly or could strain the trimmer. I always follow the manufacturer’s recommendation because that gives me the best balance between cutting power and performance.

Round vs. Twisted Line

I’ve found that line shape matters more than I expected:

  • Round line: This is usually the easiest for me to use and works well for general trimming.
  • Twisted line: I like this when I want a cleaner cut and a little less noise.
  • Square or serrated line: I use this when I need more aggressive cutting for tougher weeds.

For regular lawn edging, I usually stick with round or twisted line because they give me a good mix of control and durability.

OEM vs. Third-Party Replacement Line

When I shop, I decide between original Greenworks line and aftermarket options.

  • OEM line: I trust this for the safest fit and most reliable performance.
  • Third-party line: I consider this if I want to save money or buy in bulk, but I always read reviews first.

If I’m unsure, I usually start with OEM so I know exactly what works with my trimmer.

What I Check for Durability

I don’t want to keep stopping to reload line, so I look for products that claim:

  • High abrasion resistance
  • Less breakage on hard edges
  • Smooth feeding through the spool
  • Good performance in thick grass

In my experience, a stronger line often saves time even if it costs a little more upfront.

How I Decide on Length and Value

I compare the total length of the spool or replacement pack, not just the price. A cheaper package may not be a good deal if it runs out quickly. I usually look for a balance between cost, line quality, and how often I expect to trim.

My Tips for Easier Replacement

When I replace the line, I make sure to:

  • Clean the spool area first
  • Wind the line evenly and tightly
  • Avoid overfilling the spool
  • Trim the ends to the proper length
  • Test the feed before starting a full job

Doing this helps me avoid jams and wasted line.

My Final Buying Advice

If I’m buying Greenworks 40V trimmer line replacement, I focus on compatibility first, then durability, then price. The best choice for me is the one that fits my model, feeds smoothly, and holds up well in my yard. When I choose carefully, my trimmer works better and my yard work feels a lot easier.

Final Thoughts

I’ve found that choosing the right Greenworks 40v trimmer line replacement makes a big difference in performance and ease of use. My key takeaway is to match the line size and type to my trimmer and the kind of yard work I do. When I keep the line fresh and properly installed, my trimming goes smoother and the results look much cleaner.

Author Profile

Tessa Calder
Tessa Calder
Tessa Calder writes HexMetalsMinerals.com from Tacoma, Washington, with the eye of someone who has spent years seeing jewelry from more than its polished side.

Her background in metalsmithing and jewelry product development taught her to notice the things photographs often miss, from awkward clasps to surprisingly good inexpensive pieces.

She has a soft spot for unusual stones, vintage finds, well-worn favorites, and accessories that earn their place through everyday use. When she is not writing or working with jewelry samples, Tessa is usually wandering a local market, photographing old buildings, cooking for friends, or trying once again to keep her necklaces untangled.