Caster wheel : 81series heavy duty of4"-8" Top plate : 1.Top plate size: 98 x 114 mm; 2.Bolt hole spacing: 71 x 85mm; 3.Attaching bolt size: 11mm; 4.Top plate thickness:6.0mm Fork: 1.Fork thickness: 6.0mm; 2.Axle hole diameter: 13mm 3.Surface treatment:Brightly Galvanized Wheel: 1.wheel material: Red PU on Cast Iron, PU on PP,TPE on PP 2.wheel size:100,125,160,200 x 50mm 3.bearing: two ball bearings 4.Load Capacity:250-400kg