High load capacity up to 17.5 tons for mining and logging operations. Strong 6″ round block with yield strength over 420MPa. Solid spindle and induction hardened bearing journals. 3.5″ threaded spindle and bearing locknut, extra security with simple bearing setup and adjustment. Strong hub design machined from Spherical Granite Cast Iron. ISO M24 wheelstuds are 21% stronger than ISO M22 wheelstuds. 420×220 brake drums provide greater braking force and longer brake pad life.