Kelim, Chapter Twenty-Nine, Mishnah Four
1) The cord of the balances of goldsmiths or the weighers of fine purple cloth is regarded as a connective up to a length of three fingerbreadths,
2) The handle of an axe behind the grip, up to a length of three fingerbreadths.
a) Rabbi Yose says: if the length behind the grip is no less than one handbreadth the entire handle is unsusceptible to uncleanness.
Section one: The cord is attached to the balance in the middle and it is used to grip the balance. Three fingerbreadths are sufficient for this small cord, and therefore any longer and it is not considered connected to the balance.
Section two: The “handle” of an axe is the part directly behind the hole in which the blade is inserted. Up to three fingerbreadths of this handle are considered connected to the axe.
Rabbi Yose adds that if the handle is more than one handbreadth, it will interfere with the functioning of the axe and it is all pure.