The below capacity ranges indicate the working (dynamic) load that each caster will support. A safety factor should be included in your formula to determine your required load rating per caster.

W/(C-1)=R W is total weight needed to move. C is total number of casters required. R is ideal load rating, with safety factor built in. Divide the total load weight by one less caster than you will use to safely determine load rating.

Under 350 lbs. each
351–675 lbs. each
676–1,250 lbs. each
1,251–2,000 lbs. each
2,001–4,000 lbs. each
4,001–7,500 lbs. each
7,501–10,000 lbs. each
10,001–15,000 lbs. each
15,001–20,000 lbs. each
20,001–30,000 lbs. each
30,000+ lbs. each

12" x 4" Cast Iron Casters

Plate sizes: 8-1/2 x 8-1/2Bolt holes: 7 x 7Diameter: 8 to 16 inTread: 4, 5 inCapacity: up to 8,470 lb

8-1/2 x 8-1/2 inch top-plate casters for warehouse carts on epoxy and smooth concrete. Typical builds show wheel diameters 8 to 16 in, polyurethane and cast iron treads, and capacities 3,850 to 8,470 lb. Pair swivel and rigid casters for tracking, or use total locks where the cart must park on a grade. Larger plates spread bolt stress on thick frames under continuous tow abuse.