Caster manufacturers would produce several caster series for different load-bearing appliance or equipment. So judging a caster's specification method is to see its load-bearing.Same diameter casters, can be satisfied light-duty caster,medium-caster,heavy-duty caster,super heavy-duty caster by method of different thickness and materials of wheels and brackets making . When calculating single wheel's load-carrying,certain safety factors should be added.If ground is flat,single wheel's load-bearing = (equipment total weight+cargo's weight)/number of wheels*safety factors.If it's rough ground,single wheel load-bearing = equipment total weight+cargo's weight)/3.This algorithm,actually, added its safety factors,because there are 3 wheels supporting equipment,at least,no matter what kind of rough floors.
Caster's specification:Dimension
Generally, the larger the caster's diameter, the easier the caster's rolling and the better ability of overcoming obstacles. Caster's dimension is specified in inches. Most market trolleys used 4 or 5 inches casters in China,classified by caster's dimension.At present, on the market,popular caster dimension can range from 1 inch to 10 inches. Among the whole popular dimension, the most frequently-used caster sizes are : 2/2.5/3/3.5/4/5/6/8/10 inches.4~6 inches casters are better for shopping cart,logistics trolley,tool box,roller container,etc. Large wheel diameter will arise the center of gravity,and this will increase cost.So when choosing caster size,overall consideration is necessary.If appliances don't need move frequently,such as furniture,refrigerator,etc.,they just need to move when cleaning. In this condition,choosing sizes under 3 inches is okay.