2 Inch wheels threaded rod diameter 1/4" for wire rack and wire cloth rack. our wheels with 4 set of threaded stem adapter,when your need a 5/16”wheels,3/8”wheels Our wheels are also available as a replacement. With our threaded adapters, our wheels can be converted between 1/4" and 5/16" and 3/8". Threaded Rod Size Chart wheel with 4 set of threaded adapter ( 5/16" , 3/8" , m8 ,m10 )adapter how to use the 5/16"adapter,just screw into,so the stem 1/4" become 5/16" how to use the 5/16"adapter,just screw into,so the stem 1/4" become 3/8" Steel Wire Shelving System Casters, 2" Diameter,Set of 4,Heavy Duty 2" casters turn the steel wire shelf into a mobile storage unit. Heavy-duty steel casters are screwed into the bottom of the shelf pillars to achieve smooth rolling. Wheels are 2" in diameter. Two wheel locks for stability. Small (2" diameter) wheels Black polyurethane construction Steel swivel casters 2 locking Heavy-Duty Caster Wheels Use these easy-to-install casters to convert your Shelving unit into a rolling storage shelf unit. The wheels are made of solid polyurethane, which is durable and can run smoothly on various surfaces. The steel casters have a ball bearing rotating device for easy placement of the shelf, and 2 locking wheels can ensure your storage safety. Easy to Move. Designed for ultra-durable steel wire racking wire shelf system. Immediately upgrade the storage space with large, smoothly sliding casters for superior mobility.