What do the coloured stripes painted on the e file bits mean?

This is the designation for the “hardness” of the attachments. The globally accepted marking of nozzles, depending on the size of the grain of the diamond nozzles or the tooth of hard-alloy in its working part (graininess, roughness, hardness, “anger”) is as follows:

yellow stripe

i

minimum

superfine grain

red stripe

f

fine

fine grain

blue stripe

m

medium

medium grain

green stripe

c

coarse

coarse grain

black stripe

s

supper

very coarse grain

two black stripes

e

extra coarse

super coarse grain