How to replace grass trimmer line

Are you planning to replace the trimmer line in your grass trimmer?

Person winding mowing line into a STIHL FSA 57 cordless brushcutter

Overview: How to replace trimmer line

  • Different STIHL mowing heads, mowing lines and line spools are suitable for different applications
  • Soak mowing line in water for 24 hours before winding or use

  • To replace trimmer wire, you will either need to open the STIHL trimmer head or, with the handy comfort function, simply insert line to load it.

  • Wind the mowing line on by twisting the head

  • Alternatively, you can use a pre-filled spool

Replacing your trimmer line: the three possible methods for STIHL trimmer heads

Whether your line is worn out or you just want your brushcutter or lawn trimmer to meet new requirements, at some point it will be time to replace your trimmer line. There are basically three different methods for winding trimmer line onto a STIHL trimmer head.

Standard trimmer heads: first remove the trimmer head from the brushcutter and open it. You can then wind the replacement trimmer wire onto the exposed spool. The arrows help you to wind the trimmer line in the right direction. If you would prefer not to do this yourself, a STIHL dealer near you will be happy to help.

Comfort trimmer heads: with these trimmer heads, you can conveniently wind on the trimmer line from the outside. Simply insert the desired length of line into the trimmer head, then wind it around the line spool by turning the underside of the trimmer head. This winds the line onto the spool with no need to take the head apart. The only thing you need to take care of here is ensuring that equal lengths of trimmer line protrude from both sides of the trimmer head before winding. Trimmer heads with this comfort feature are identified by the letter “C” in the model name.

There is also a third option for replacing trimmer wire that is suitable for both standard and comfort trimmer heads: open the trimmer head and insert a pre-filled spool.

The right mowing line for any challenge

Are you planning to replace your trimmer line and wondering which line is best for your STIHL brushcutter? As a general rule of thumb, the longer and denser the grass to be cut, the thicker the line should be. STIHL trimmer lines come in different colours, each representing a specific diameter, for better recognisability and orientation. For example, red mowing lines always have a diameter of 2.7 millimetres.

But be aware: the thicker the line, the more power you need to achieve a clean cut. So understanding which trimmer line is right for you means considering both the mowing heads and the appropriate lawn trimmers, clearing saws and brushcutters.

To help you keep track of the key points, we have put together a summary of all the important information about mowing lines, mowing heads and mowing blades on our product accessory pages. 

Preparing the mowing line for winding and proper storage

Last but not least, to ensure appropriate storage and optimal preparation of your mowing line, we recommend that you soak the trimmer line in water for 24 hours before use.

Plastic container of unwound trimmer line and a STIHL trimmer head

Mowing lines lose moisture and thus elasticity over time. Immersing them in water helps them to recover both, which ensures they wear out less quickly.

By the way, there’s no need to unwind the thread for soaking: you can simply place the loaded spool of trimmer line directly into water.

Doing this also means you won't have to worry about storing your line: you can simply leave it in your grass trimmer until the next time you use it.

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