How to replace a line trimmer head

Eventually you’ll need to replace the mowing line, cutting head or blade on your line trimmer or brush cutter. Our guide and videos tell you how to do it easily and quickly.

A grass trimmer being held upside down as someone wearing gloves inspects the metal cutting tool


How to replace a line trimmer blade


Different cutting tools need different processes. Check that the approved deflector for the STIHL replacement trimmer head head is fitted. The correct deflector and mounting can be found in the operating instructions. The videos below show how to replace the blade as well as replacing line in a number of our trimmer heads.

Video instructions: how to replace a grass trimmer head

Summary: Attaching a STIHL trimmer head replacement

  • Wear appropriate protective clothing and follow the steps in the operating instructions for your trimmer
  • The line spool must face upwards and the approved deflector for the wire and grass trimmer must be fitted
  • Lock the shaft with a lock pin or Allen key
  • To replace a wire: fit the new grass trimmer head and tighten it while the shaft is locked
  • To replace a metal cutting tool: place the metal blade onto the thrust plate, fit the thrust washer and rider plate onto the shaft, and tighten the nut
  • Remove the tool and release the locked shaft