The axlebox bearing for freight cars is a core safety component of the freight running gear. Compared with passenger and metro bearings, freight bearings carry heavier axle loads, more frequent impact loads, harsher operating conditions and much longer maintenance intervals, which sets higher demands on steel cleanliness, case depth and residual-stress control. The range is based on the double-row tapered roller design and covers the main sizes 353130B, 353132A and 352226X2-2RZ. Made from carburising bearing steel and put through controlled-atmosphere carburising, re-hardening and stabilising tempering, rings and rollers develop a fine martensitic structure and an even hardness gradient; the integral self-sealing design with long-life grease keeps the bearing running reliably under heavy loads, dust and wide temperature swings. The product reaches advanced international standards, with annual capacity of 400,000 new and 150,000 reconditioned sets, ranking first in China in both output and market share, and supplies China Railway and the rolling stock companies of CRRC.