... diameter: 75mm,100mm, 125mm3.Caster material: Hard rubber with delrin bearing,pressed steel,zinc plated,double ... -spray and finish treatment testing to ensure high corrosion-resistance.Now it already has become ... wheel diameter is from 15mm to 300mm, materials include rubber, TPR, PU, plastic, nylon, cast iron, pneumatic ... . Factory 65 American type hard rubber ball caster threaded stem side brake caster