A braking band of a disc for disc brake of ventilated type, - said braking band extending between an inner diameter (D1), near a rotation axis (X-X) of the braking band , and an outer diameter (D2), far from said rotation axis (X-X), said rotation axis defining an axial direction (X-X); - said braking band defining a radial direction (R-R), substantially orthogonal to said axial direction (X-X), and a circumferential direction (C-C), orthogonal to said axial direction (X-X) and to said radial direction (R-R), and a tangential direction (T-T) punctually orthogonal to said axial direction (X-X) and a radial direction (R-R); - said braking band comprising two mutually facing plates ; said plates comprising inner surfaces , either directly or indirectly facing and delimiting a gap ; - said plates comprising a plate body having a predetermined extension in axial direction (X-X) or predetermined plate thickness ; - said plates being joined to each other by heat dissipating and connecting elements , also named connecting elements; - said connecting elements being shaped as columns and/or ribs and/or fins which project from a plate towards the opposite plate, whereby forming bridges which connect the plates to each other; wherein - wherein one of the plates (3; 4) comprises at least one ridge which projects from said plate (3; 4) into said gap without reaching the opposite plate (4; 3), whereby forming at least one localized narrowing of said gap and a thickening of the plate body (12; 13), whereby creating a localized increase of said plate thickness (14; 15); characterized in that : - said at least one ridge remains separated from each connecting element , wherein the thickness of at least one plate (3; 4) about said at least one ridge is substantially equal to said predetermined plate thickness ; and - said at least one ridge extends forming at least two separate ridge branches . - said braking band extending between an inner diameter (D1), near a rotation axis (X-X) of the braking band , and an outer diameter (D2), far from said rotation axis (X-X), said rotation axis defining an axial direction (X-X); - said braking band defining a radial direction (R-R), substantially orthogonal to said axial direction (X-X), and a circumferential direction (C-C), orthogonal to said axial direction (X-X) and to said radial direction (R-R), and a tangential direction (T-T) punctually orthogonal to said axial direction (X-X) and a radial direction (R-R); - said braking band comprising two mutually facing plates ; said plates comprising inner surfaces , either directly or indirectly facing and delimiting a gap ; - said plates comprising a plate body having a predetermined extension in axial direction (X-X) or predetermined plate thickness ; - said plates being joined to each other by heat dissipating and connecting elements , also named connecting elements; - said connecting elements being shaped as columns and/or ribs and/or fins which project from a plate towards the opposite plate, whereby forming bridges which connect the plates to each other; wherein - wherein one of the plates (3; 4) comprises at least one ridge which projects from said plate (3; 4) into said gap without reaching the opposite plate (4; 3), whereby forming at least one localized narrowing of said gap and a thickening of the plate body (12; 13), whereby creating a localized increase of said plate thickness (14; 15); characterized in that : - said at least one ridge remains separated from each connecting element , wherein the thickness of at least one plate (3; 4) about said at least one ridge is substantially equal to said predetermined plate thickness ; and - said at least one ridge extends forming at least two separate ridge branches . <EOS>