Weed Eater Blades vs. String: Which Should You Use?

If there were only one cutting option that worked best on a weed eater, we wouldn’t need to discuss the different types. However, there’s a reason you’ll find multiple choices at the store. Each has its strengths and is made to handle certain tasks.

What’s ideal for routine grass could be the wrong choice for thicker weeds or brush. The area you’re working in, how the attachment wears, and what your machine can use also affect the decision. This guide breaks down these differences to help you choose the right cutting option for the job.

Table of Contents

• What’s the Difference Between Weed Eater String and Blades?
• Which Is Better for Grass, Weeds, Brambles, and Tough Vegetation?
• When Should You Use String Instead of a Weed Eater Blade?
• When Should You Use a Plastic Blade Instead of String?
• When Should You Use a Metal Blade Instead of String?
• How Does the Working Environment Change the Choice?
• How Do String and Blades Compare for Durability and Maintenance?
• Can You Use a Blade on Any Weed Eater?
• Conclusion
• FAQs About Weed Eater Blades vs String

What’s the Difference Between Weed Eater String and Blades?

Weed eater string is a flexible nylon line, while plastic and metal blades have more rigid cutting edges. They do not respond to vegetation or obstacles in quite the same way.

A string trimmer spins line out from the trimmer head. The line can flex when it meets resistance and gradually wears down as you work. Plastic blades keep a defined cutting edge, but their shape and intended use vary. Metal blades also come in different styles. Some are made for grass and weeds, while others are designed for brush or heavier growth.

The difference is not simply that one attachment is more powerful than another. What matters is the cutting job each was designed to do.

Which Is Better for Grass, Weeds, Brambles, and Tough Vegetation?

Grass and light weeds are generally well suited to string. As vegetation gets thicker and tougher, string can become less practical, while the right blade may handle the work more effectively. The following comparison gives you a starting point before you consider the specific attachment and machine.

Weed Eater String vs Plastic and Metal Blades for Different Vegetation

Vegetation	String	Plastic blade	Metal blade
Routine grass	Well suited	May be suitable if approved	Often unnecessary
Light weeds	Generally suitable	May be suitable	Suitable designs can handle them
Thick grass	May wear more quickly	Depends on blade design	A suitable grass blade may help
Dense weeds	Can become less practical	Depends on blade design	Use a suitable weed blade
Brambles	Less suited to clearing	Usually not the intended choice	Use a suitable brush blade
Tough woody growth	Not the intended choice	Not the intended choice	Only suitable brush-cutting designs

These categories are not absolute. Thick grass is different from woody brush, and not every metal blade is designed for the same material. Use the table to narrow the choice, then check what the particular blade is designed to cut.

When Should You Use String Instead of a Weed Eater Blade?

Use string when you’re mostly trimming grass and light weeds, particularly when the job involves shaping and cleanup rather than clearing heavy growth. For many day-to-day jobs, the line you already have on the trimmer is doing exactly what you need.

Trimming along lawn edges and working around trees, fence posts, and garden beds is easier to manage without a stiff blade. String has some give when it contacts an obstacle. That does not mean it cannot wear down or damage bark and other surfaces, but its flexibility makes it useful for close trimming.

String also takes care of many light weeds. You don’t have to change attachments just because some softer weeds are growing among the grass. Once you run into thick, hard growth that repeatedly breaks or wears through the line, though, finishing the job with string can become frustrating.

When Should You Use a Plastic Blade Instead of String?

A plastic blade can be useful for grass and light weeds when you want a more defined cutting edge than flexible line provides. It is an option for certain trimming jobs on machines designed to use it, not a necessary step between string and metal.

However, different plastic blades have different limits, and they do not offer the same flexibility for close work around obstacles. Check the blade’s intended use and whether your trimmer accepts it before choosing a plastic blade for a particular job.

When Should You Use a Metal Blade Instead of String?

Use a suitable metal blade when thicker weeds, brambles, or brush make string impractical and your machine is designed for blade use. A rigid blade can handle demanding growth without being consumed like trimmer line, but the blade must match what you are cutting.

The key is the type of metal blade. A grass or weed blade may be designed for heavier non-woody vegetation. Brush and woody stems may require another design or tooth configuration. That is why “use a metal blade” is not a complete answer when the job moves beyond ordinary weeds.

If you are dealing specifically with thick grass, our brush cutter blade vs trimmer line comparison for thick grass looks more closely at that choice.

How Does the Working Environment Change the Choice?

String is generally easier to manage near obstacles, while rigid blades need more clearance. Avoid using a metal blade where contact with rocks, concrete, wire, or other hard objects is likely.

Weed Eater String vs Plastic and Metal Blades Around Obstacles

Working condition	String	Plastic blade	Metal blade
Trees and planted borders	More flexible for close trimming; avoid contact	Keep clear of plants	Avoid close contact
Fences and walls	Useful for close trimming; line can wear	Avoid strikes	Avoid contact
Rocks and concrete	Keep clear where possible	Avoid strikes	Avoid where strikes are likely

Even flexible line can damage bark and other surfaces. Plastic blades can also be damaged by impacts. If you find wire, loose stones, or other hard debris, clear or avoid the area first. Switching attachments does not make a hidden-object strike safe.

How Do String and Blades Compare for Durability and Maintenance?

String needs regular replenishment; blades need regular inspection. How quickly any attachment wears depends on what you cut and how often it contacts the ground or other objects.

The table below summarizes the typical wear and maintenance differences between weed eater string, plastic blades, and metal blades.

Weed Eater String vs Plastic and Metal Blade Durability and Maintenance

Factor	String	Plastic blade	Metal blade
Normal wear	Frays and shortens	Cutting edge wears	Cutting edge dulls
Wear under demanding use	Faster line consumption	Wear or damage beyond intended use	Wear varies by blade and vegetation
Routine maintenance	Advance or replace line	Inspect and replace as needed	Inspect; sharpen if permitted
Damage requiring replacement	Broken or damaged line	Chipped or cracked blade	Cracked, bent, or damaged blade

A job may be possible with string but still use enough line to make it inconvenient. A plastic blade can also wear or chip, especially if the work exceeds what it was designed to handle.

Metal blades can last much longer than line, but they still wear and can be damaged. Some can be sharpened according to the manufacturer’s instructions, but sharpening will not fix a cracked, bent, or otherwise damaged blade. Inspect it before use and replace it when it is no longer serviceable.

Can You Use a Blade on Any Weed Eater?

No. Swapping out the string head does not make every weed eater suitable for a blade. Check which attachments and required equipment the manufacturer approves for your model. We cover the details in Can You Put a Brush Cutter Blade on a String Trimmer?.

Conclusion

Deciding when to use string, plastic, or metal depends on the job. String handles grass and light trimming most of the time, especially when you need to work near trees, fences, or landscaping. A plastic blade may be useful for grass and light weeds if your machine accepts it and you want a more rigid cutting action.

Heavy weeds or tough brush may call for an appropriate metal blade. The blade still has to suit the vegetation, and the working area must be appropriate for using it. Ultimately, choose the attachment that can handle the job without asking more from the machine or cutting system than it was designed for.

FAQs About Weed Eater Blades vs String