Are bumper plates really being made in ridiculous sizes of tiny differences?

I know Hi-Temps are 445mm intentionally. But when I look at other bumper plate manufacturers, sizes are quoted as 17.5 (Hi-Temp size) and then 17.7, 17.72, and 17.75 inches. Is this just sloppy metric conversion or do the sizes really vary that much and does it matter? I currently use a pair of rep 55lb bumper plates plus some smaller REP black bumper plates (that are all the same size as far as I can tell but I never tried to measure with a microscope). I have to add a significant amount of iron to deadlift weights. I ordered another set of the REP 55lbs but Walmart has some cheaper 45s in stock. (Cheap for pandemic prices). I was going to order them but if they are 17.75" vs the normal 450mm, I'm worried that they will break if I put a single deadlift down harder than intended. REP is actually the worst offender since they don't seem to specify a size at all (Only indicate that Hi-Temps are "smaller." I'm inclined to just not mix and match manufacturer's plates but that seems like an expensive an unfair solution.

To the best of my knowledge Hi-Temps are 445 mm and the ones from Rogue, Titan, Vulcan and Rep are all 450 mm.

I am not a fan of some of the budget plates which have larger inside diameters (51mm vs 50.4). I wouldn't use 17 3/4" plates with 450 mm ones for deadlifts. If it voids Rep's warranty to use Hi-Temps with their 450 mm ones, I doubt many manufactures would cover using their 17 3/4" plates with someone else's 450 mm ones.

Although Rep does list the diameter of some bumper plates, their competition ones are 450 mm. Also, a Google search will reveal that their standard plates are also 450 mm. If I was planning on ordering Rep plates I would email or call them to confirm the exact diameter.

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Originally Posted by Logan1

To the best of my knowledge Hi-Temps are 445 mm and the ones from Rogue, Titan, Vulcan and Rep are all 450 mm.

I am not a fan of some of the budget plates which have larger inside diameters (51mm vs 50.4). I wouldn't use 17 3/4" plates with 450 mm ones for deadlifts. If it voids Rep's warranty to use Hi-Temps with their 450 mm ones, I doubt many manufactures would cover using their 17 3/4" plates with someone else's 450 mm ones.

Although Rep does list the diameter of some bumper plates, their competition ones are 450 mm. Also, a Google search will reveal that their standard plates are also 450 mm. If I was planning on ordering Rep plates I would email or call them to confirm the exact diameter.

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Thank you. The plates I already own are Rep so I just ordered more in order to avoid the hassle. I like the Rep plates that I have. Nice and quiet even if I set a deadlift down harder than I intended. They aren't "snug" together on the bar but I have Eleiko competition collars that keep the plates nice and manicured. I would have liked to have saved some money. If I find anybody who has economy plates, I will see if there is any actual difference. I appreciate your answer.

As you said, it's also possible that the other plates really are 450 mm but the conversion to inches is off a bit. I would contact the manufacturer rather than Walmart to be sure.

Always glad to share my modest knowledge of equipment. As long as I was starting with quality plates, like Rep's, I would have made the same choice.

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Originally Posted by Logan1

Always glad to share my modest knowledge of equipment. As long as I was starting with quality plates, like Rep's, I would have made the same choice.

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My buddy found some cheap bumpers in stock at Walmart today. We had basically the exact same conversation as this thread. So I guess we will find out. In the interim, we also discovered that Titan Fitness sells bumper plates that are 450mm/17.75" at the same time. Apparently they are quantum bumper plates that can exist in two different states at once?!

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