Metal belt and method for producing such

A method of producing a drive belt for a continuously variable transmission, the drive belt having

• an endless metal band assembly, provided as a set of nested metal bands, and at least partly surrounded by transverse elements for at least clamping the drive belt in between sheaves of a set of a pulleys,
• one of the nested metal bands being provided with
• a central portion having a cross-section, the cross-section having a minimal but consistent degree of greater thickness than surrounding lateral portions,
• first and second lateral faces, and
• a first contact face with a first curvature (R1) and a second contact face with a second curvature (R2), both contact faces being smoothly curved,
• each of the first and second curvatures defining a circular radius greater than one meter, and
• wherein the one band is substantially symmetrically shaped in respect of an imaginary plane located centrally between the first and second lateral faces (L) of the one band, comprising the steps of:
• deforming the one band by leading the one band between surfaces of two deformation elements adapted for creating a band contact face corresponding to the one band;
• subsequently annealing the one band;
• and
• thereafter heating the one band in a nitrogen environment to chemically create a superficial permanent compression layer.