Threaded Type 420Ea Swivel Caster, Nylon Solid Wheel 420A-N50

Because there was no 75 mm diameter castor of nylon material in the rack maker, I bought it. From the manufacturer, it was said that "non genuine goods are not recommended", but this product made in Japan is better for mental hygiene than the genuine products made in China, the price was also cheap. I use it on a carpet and I am saved because I can move as much as I am at an old age. Because the rack can be a little special structure, the manufacturer's safety factor (dynamic load) and the general safety factor that can be applied to non-genuine domestic casters are far apart, so it is a little lost. Calculating based on the stationary ratio on the rack side results in a load of 40 kg for four wheels and 160 kg for the same based on the safety factor on the caster side.

It is strong and slippery. I think that it will last as it is likely to have durability against the paint on the floor than the rubber wheels.

I could not fix it unless I prepared an extremely thin spanner (generally not available) for installation and I had a hard time. It seems to lower the height of the ground, but I want a thickness of hexagon part a bit more to devise an offset.