Here is an English product description for an automotive "花键套" (Spline Sleeve), with the first paragraph exceeding 500 characters:
Precision Spline Sleeves: The Essential Link for Robust Torque Transmission in Automotive Drivetrains
Engineered for seamless power transfer and unwavering reliability, our Spline Sleeves (also known as Spline Couplings or Spline Bushings) represent a critical, high-precision component within modern automotive drivelines. Meticulously manufactured to exacting tolerances, these sleeves feature intricate internal and/or external splined profiles designed to interlock perfectly with mating shafts, gears, or hubs, creating a torsionally rigid connection that efficiently transmits high torque while accommodating necessary axial movement or misalignment. Constructed from premium-grade, case-hardened alloy steels or specialized engineered materials, they undergo rigorous heat treatment processes to achieve an optimal balance of exceptional surface hardness for…