1. Product Overview The 77730 four‑row tapered roller bearing, new designation 381030X2, is multi‑row heavy‑duty taper roller unit. It can bear huge combined radial and axial loads, adjustable working clearance, designed for low‑speed heavy‑impact operating conditions for metallurgical rolling mill main roller shafts. It is widely used for steel rolling mills, heavy mining equipment and large‑size heavy‑duty industrial rotary shafts. 👉 Get a quote within 24 hours for your