Standard top plate scaffold casters CAS12P Series are designed for scaffolds 3300lbs to 5000lbs load capacity per caster, features and easy to engage total locks that locks both wheel and swivel and allow easy locking and respositioning. Top plate fitting, zinc swivel caster, housing and plate steel-welded, bright zinc plated, double steel ball raceway, threaded king pin and nut be riveting rushed secured or weled, grease nipple, wheel axle choose 8.8 safe bolt. Wheel center made of cast iron, Tread: good quality rubber, durable ball bearings.