A seal assembly including a coning-resistant rotor that is generally ring-shaped in structure and comprises: a rotor base connected to a shaft , the shaft being rotatable about an axis having a centerline (CL), wherein an axial clamping force (CF) is applied to the axial front and rear of the rotor base ; a rotor head including a rotor face on the front axial side having a sealing surface; and an axially-extending web interposed between the rotor base and the rotor head 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 , 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 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 . a rotor base connected to a shaft , the shaft being rotatable about an axis having a centerline (CL), wherein an axial clamping force (CF) is applied to the axial front and rear of the rotor base ; a rotor head including a rotor face on the front axial side having a sealing surface; and an axially-extending web interposed between the rotor base and the rotor head 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 , 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 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 . <EOS>