Moulding element of a mould for moulding and vulcanizing a tyre tread, this tread comprising a tread surface intended to come into contact with the ground when the said tyre is rolling. The moulding element (1) comprising a moulding surface (3) intended to mould part of the tyre tread surface and a blade (5) of height H intended to mould a sipe or a groove in the tread, this blade extending in a first direction of extension Y. The moulding element comprises two cutting means (7) positioned on either side of the blade (5) at a certain distance from this blade. The moulding element comprises a third cutting means (11) of height He extending in a second direction of extension X, this second direction of extension X making an angle a with the first direction Y which is comprised between 75° and 105°. The height He of the third cutting means (11) is greater than the height H of the blade (5).