The SKF 51104 is a single-direction thrust ball bearing with a 20mm inner diameter, 35mm outer diameter, and 12mm thickness. Made of GCr15 high-carbon chromium steel with a pressed steel cage, it withstands unidirectional axial loads only. Ideal for low-speed, high-precision axial positioning applications (e.g., machine tool lead screws, chemical equipment axial supports, automation machinery adjustment mechanisms), it offers a compact design, high axial rigidity, and light corrosion resistance.