A seal assembly including a coning-resistant rotor (10, 70) that is generally ring-shaped in structure and comprises: a rotor base (12, 74) connected to a shaft, the shaft being rotatable about an axis having a centerline, wherein an axial clamping force is applied to the axial front and rear of the rotor base (12, 74); a rotor head (16, 76) including a rotor face (18, 78) on the front axial side having a sealing surface; and an axially-extending web interposed between the rotor base (12, 74) and the rotor head (16, 76) to connect the rotor base to the rotor head, the axially-extending web including: at least two axially-extending circumferential grooves, a radial web region formed, at least in part, by the axially-extending circumferential grooves; the axially-extending circumferential grooves comprising a first axially-extending circumferential groove forming a rear axial web region and a second axially-extending circumferential groove forming a front axial web region, wherein the first axially-extending circumferential groove is formed into the web from a front portion of the rotor (10, 70), and the second axially-extending circumferential groove is formed into the web from a rear portion of the rotor, wherein the first axially-extending circumferential groove and the second axially-extending circumferential groove are provided at different radial positions relative to each other, and wherein, viewed in cross-section along a circumferential direction, the web has a substantially "S"-shaped configuration, characterized in that: the rotor base includes a channel provided at an inner diameter of the rotor base (12, 74) adjacent to the rotor shaft and the channel includes a taper extending along the axial length of the channel and having a high point at its front axial end near the front axial side of the rotor base (12, 74). a rotor base (12, 74) connected to a shaft, the shaft being rotatable about an axis having a centerline, wherein an axial clamping force is applied to the axial front and rear of the rotor base (12, 74); a rotor head (16, 76) including a rotor face (18, 78) on the front axial side having a sealing surface; and an axially-extending web interposed between the rotor base (12, 74) and the rotor head (16, 76) to connect the rotor base to the rotor head, the axially-extending web including: at least two axially-extending circumferential grooves, a radial web region formed, at least in part, by the axially-extending circumferential grooves; the axially-extending circumferential grooves comprising a first axially-extending circumferential groove forming a rear axial web region and a second axially-extending circumferential groove forming a front axial web region, at least two axially-extending circumferential grooves, a radial web region formed, at least in part, by the axially-extending circumferential grooves; the axially-extending circumferential grooves comprising a first axially-extending circumferential groove forming a rear axial web region and a second axially-extending circumferential groove forming a front axial web region, wherein the first axially-extending circumferential groove is formed into the web from a front portion of the rotor (10, 70), and the second axially-extending circumferential groove is formed into the web from a rear portion of the rotor, wherein the first axially-extending circumferential groove and the second axially-extending circumferential groove are provided at different radial positions relative to each other, and wherein, viewed in cross-section along a circumferential direction, the web has a substantially "S"-shaped configuration, characterized in that: the rotor base includes a channel provided at an inner diameter of the rotor base (12, 74) adjacent to the rotor shaft and the channel includes a taper extending along the axial length of the channel and having a high point at its front axial end near the front axial side of the rotor base (12, 74).