How to find the right round file

You can resharpen the cutting teeth of your chipper-tooth chain with a round file on your own. But a word of caution: not every saw chain is the same. The tool you use needs to match the respective saw chain, because if the wrong file is used, it can diminish the cutting performance of the chain. We explain below how to find the right round file.

STIHL round file for saw chains

STIHL round file for saw chains

Selecting the right round file depends on the chain pitch of the saw chain. Each chain pitch is assigned to a specific round file diameter.

The chain pitch assigns the saw chain to particular chainsaw models (power classes). To determine the pitch, measure the distance from the centre of one rivet to the centre of the next but one and then divide the measurement by two. The result is the chain pitch in millimetres. However, since the chain pitch is always given in inches, you will then need to convert the result (1 millimetre = 0.039 inches).

For STIHL saw chains, a number to identify the chain pitch is located on the outer edge of the depth gauge. Read our article “How a STIHL saw chain functions” to find out about the construction of a STIHL saw chain. In our example it is number 3.

The chain pitch code number

The chain pitch code number is located on the depth gauge

The larger the chain pitch, the higher the tooth. The higher the tooth, the larger the file needs to be.

If the number on the depth gauge is no longer legible, the chain pitch can be determined using a test gauge for chains.

Subsequently you can find the necessary file diameter using the STIHL conversion table:

STIHL conversion table to find the right round file

STIHL conversion table to find the right round file based on chain pitch

A word of caution: Please note that saw chain files have a different profile, i.e. a different surface structure, than engineer’s files, for example. The latter are therefore unsuitable to file saw chains.

All STIHL files are available at your local STIHL dealer.

On our website, you will find a detailed tutorial on how to sharpen saw chains.

Note: Only side-plate and top-plate cutting edges are sharpened with a round file. You should file back the depth gauge using a flat file so that it keeps its shape.

If you want to sharpen the cutting teeth and file back the depth gauge at the same time, we recommend you to use the STIHL 2-in-1 file holder.

All mentioned STIHL products are available at your local STIHL dealer.

Read comments and comment:

2 thoughts on “How to find the right round file

  1. Should I use a 5/32″ round file on a still chain 71 PM3 (10″ micro chain) ?

    Or, should I use a 1/8″ round file as listed in my sharpening tool ( special accessories) in my Stihl HT 56 C manual and also on the replacement chain box?

    I am confused for sure!!!

    1. Hello Bernard,
      Thank you for your comment.
      Please use a roundfile with 1/8″ (3,2 mm) diameter for resharpening your 71PM3 chain as mentioned in the manual and in our blogpost.
      Best regards,
      your STIHL team

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