Bumper Plate Brands, Types, Differences?

I’ve just invested in some inexpensive bumpers from Pendlay. They are fine, and excellent considering the price. But the 45 pound ones are 3.5 inches thick. So, the most that will fit on a regular 84" bar adds up to about 405 pounds.

Yet I’ve seen people lifting way more than 405 on a standard bar with bumpers. So, do the higher end ones use denser rubber or something?

The ones that cost more are:
Going to last longer
Have a metal inside so that the metal collar on the inside wehre you slide your weight last longer. A few York weights we’ve had at the club the metal centere is broken/ falling to pieces but granted they have been there about 20-25yrs+ at the club!
Denser so you can fit more weight on the bar
Calibrated for competition use : not important for most people


The higher quality ones have metal (steel) cores.

The cheaper ones made from recycled rubber are thicker, but aren’t bad for training and I suspect that they are more forgiving to platforms and floors precisely because they are not so dense. And the ones with the steel inserts are said to have great longevity (the ones with brass inserts less so).

There is the problem of bar space when you begin pushing heavy weights, though.

I found one review here, but it only covers two brands. And it does not indicate the thickness of the plates (except to say one is thicker than the other):

Does anyone have any comments or links to reviews on particular brands?

Thanks in advance.