4X4'' Caster pad with nut and bolt pad material: steel carriage bolt size:3/8X5'' Heavry duty caster pad size:4X6'' Caster pad4X4'' caster pad with nut and bolt Material:caster pad: steel with natural colorBolt and nut: steel with Zinc on surface.Size:Standard caster pad: 4X4'' Heavy duty caster pad: 4X6''Carriage bolt: 3/8X5''Specification:Quick change caster pad for ease of installation of ...