Choosing the correct strimmer line can make a huge difference to your garden maintenance. The right line can improve cutting performance, reduce breakages, extend runtime, and help your strimmer tackle everything from light grass trimming to heavy weeds and overgrown areas.

With so many line sizes, shapes, and materials available, it can be difficult to know which option is best for your machine.

In this guide we explain how to choose the correct strimmer line for your strimmer and your gardening needs.

Why Choosing the Right Strimmer Line Matters

Many performance problems can be traced back to using the wrong line.

Incorrect line can cause:

• Poor cutting performance

• Frequent breakages

• Feeding problems

• Excessive vibration

• Increased strain on the motor

Using the correct line helps your strimmer work efficiently and can extend the life of the machine.

Step 1 – Check Your Strimmer's Recommended Line Diameter

The first thing to check is the manufacturer's recommended line size.

Most strimmers are designed to use a specific diameter range.

Common line diameters

Using line that is too thick can cause feeding issues and place extra strain on the machine.

Using line that is too thin may result in frequent breakages.

Step 2 – Consider What You Are Cutting

Different gardening tasks require different line types.

Light Grass

For regular lawn edging and light trimming:

• Round line

• Smaller diameters

• Standard nylon line

usually work well.

Thick Grass

For denser growth:

• Twisted line

• Square line

• Larger diameters

often provide better cutting performance.

Weeds and Tough Vegetation

For tougher jobs:

• Square line

• Serrated line

• Heavy-duty nylon line

can improve efficiency.

Step 3 – Choose the Correct Line Shape

Line shape affects both cutting performance and durability.

Round Line

The most common type.

Benefits

• Easy feeding

• Good durability

• Suitable for most domestic users

Ideal for general garden maintenance.

Square Line

Square edges provide a more aggressive cutting action.

Benefits

• Cuts thicker vegetation

• Improved efficiency in dense grass

Drawbacks

• May wear more quickly on hard surfaces

Twisted Line

Designed to improve cutting efficiency while reducing noise.

Benefits

• Quieter operation

• Smooth cutting

• Reduced vibration

Popular with domestic users.

Serrated Line

Features cutting edges designed for tougher vegetation.

Benefits

• Excellent cutting power

• Effective on weeds and dense growth

Typically used in more demanding applications.

Step 4 – Consider Your Strimmer Type

Not all strimmers are designed for heavy-duty line.

Cordless Strimmers

Generally perform best with lighter line sizes.

Electric Strimmers

Usually use light to medium-duty line.

Petrol Strimmers

Often capable of handling larger diameter line for demanding work.

Always check the manufacturer's specifications.

Step 5 – Check Spool Compatibility

Some strimmers use specific spool designs.

Before purchasing replacement line, ensure:

• The spool supports the chosen diameter

• The line can feed correctly

• The spool capacity is not exceeded

Overfilling the spool is a common cause of feeding problems.

Signs You're Using the Wrong Line

Line Too Thin

• Frequent breakage

• Poor cutting performance

• Difficulty tackling thicker grass

Line Too Thick

• Feeding problems

• Motor strain

• Reduced performance

Choosing the correct balance is important.

Which Strimmer Line Is Best for Most Homeowners?

For most domestic gardens:

Recommended choice

• 1.6mm to 2.0mm diameter

• Round or twisted nylon line

This combination offers a good balance of:

• Durability

• Cutting performance

• Reliable feeding

How This Relates to Other Strimmer Problems

Incorrect line selection is often responsible for common strimmer faults.

For example:

• If the line keeps snapping, see Strimmer Line Keeps Breaking – Causes and Fixes

• If the line will not advance, read Why Is My Strimmer Line Not Feeding? Causes and Fixes

• If the machine vibrates excessively, see Strimmer Vibrating Excessively – Causes and Fixes

When Replacement Parts May Be Needed

If changing the line does not solve performance issues, other components may need attention.

Common parts associated with line-related problems include:

• spools

• spool covers

• strimmer heads

• bump-feed mechanisms

Replacing worn parts can often improve reliability.

You can find replacement strimmer line, spools, spool covers, and complete strimmer heads for many popular brands from Yourspares.

Final Thoughts

Choosing the correct strimmer line is one of the easiest ways to improve cutting performance and reduce frustration while working in the garden.

By selecting the right diameter, shape, and type of line for your machine and the job at hand, you can achieve cleaner cuts, fewer breakages, and more efficient operation.

Related Garden Equipment Advice

• Why Is My Strimmer Line Not Feeding? Causes and Fixes

• Strimmer Line Keeps Breaking – Causes and Fixes

• Strimmer Head Not Spinning – Causes and Fixes

• Strimmer Not Cutting Properly – Causes and Fixes

• How to Replace a Strimmer Spool

• How to Wind Strimmer Line Correctly

• Strimmer Line Sizes Explained