Sliding ring

A sliding ring comprising:

• a faying face having a recessed surface and a non-recessed surface, wherein the sliding ring has a first axial thickness at a location on the recessed surface and the sliding ring has a second axial thickness at a location on the non-recessed surface and the ratio of the first axial thickness to the second axial thickness is in a range from 0.25 to 0.50;
• a plurality of symmetrical bell-shaped grooves each having two lower walls, two upper walls, a height, a top width, and a base width, situated radially on the recessed surface wherein the bell-shape has a first inclination angle from 5° to 15° formed between each of the lower walls and radial lines extending from a lowermost endpoint of each lower wall, a second inclination angle from 5° to 45° formed between each of the upper walls and lines extending from an uppermost endpoint of the upper wall, said lines being parallel to the top width, and wherein the ratio of the base width to the top width is from 2 to 6;
• a portion of the non-recessed surface in the shape of a circumferential band;
• a thin circumferential groove located on a perimeter between the bases of the bell-shaped grooves and abutting the circumferential band, and having a height, wherein the ratio of the height of the thin circumferential groove to the height of the bell-shaped grooves falls within a range of 0.08 and 0.25.