Abstract: Mould for moulding a tread of a tire, this tread having a thickness of material to be worn away and a tread surface intended to come into contact with the road surface when the tire is running, this mould having a moulding surface intended to mould the tread surface of the tread, and having a moulding element formed of a blade and a bar, the blade being attached to the moulding surface to mould a sipe in the tread, the bar, borne by the blade to form an enlarged part of maximum width D, being intended to mould a channel in the tread, this channel itself being intended to form a new groove when the tread becomes part worn. Each blade is delimited by two lateral faces forming between them a mean angle of between 6° degrees and 18°. The blade width decreasing from the mould surface when new, as far as the connection with the bar, the blade width meets the bar being at least equal to between 0.2 and 0.4 times the maximum width D.

Abstract: Mould for moulding a tread of a tire, this tread having a thickness of material to be worn away and a tread surface intended to come into contact with the road surface when the tire is running, this mould having a moulding surface intended to mould the tread surface of the tread, and having a moulding element formed of a blade and a bar, the blade being attached to the moulding surface to mould a sipe in the tread, the bar, borne by the blade to form an enlarged part of maximum width D, being intended to mould a channel in the tread, this channel itself being intended to form a new groove when the tread becomes part worn. Each blade is delimited by two lateral faces forming between them a mean angle of between 6° degrees and 18°. The blade width decreasing from the mould surface when new, as far as the connection with the bar, the blade width meets the bar being at least equal to between 0.2 and 0.4 times the maximum width D.

Abstract: A process in which a steel is dipped in an aluminum-based bath wherein the composition and mean temperature of the bath and the immersion temperature of the steel are adjusted to obtain, in the immersion zone of the steel, a local bath temperature and composition resulting in an equilibrium with the solid phase designated as &thgr;≡FeAl3. Dipping is performed at a temperature higher than the temperatures normally employed in the art and a coating is obtained having at the interface with the steel an alloy layer significantly smaller in thickness than the art. The coating obtained better resists cracking and corrosion.