Various manufacturers of Olympic and weightlifting plates use different standards for accuracy. Is there a good resource for comparing price versus accuracy? Can anyone suggest some manufacturers and supply some reasonably trustworthy data as to their plates' accuracy?
Unless a manufacturer specifies the accuracy that they test their plates with, the weight can be off by a few percentage points from the nominal weight. Of course, if the plates are IWF certified, they go through an independent review process to make sure they are within specification.
MuscleDriverUSA has a good reputation for shipping plates at the same weight they are advertised. They have "econ" plates that ship at +/- 10g which is a variance within the range of "don't care". They also have reduced price failed color plates that are +/- 25g which again is insignificant.
Rogue Fitness has a mix of plates, and if they don't specify accuracy, the plates will have a significant variance. They do advertise some colored plates that are +/- 10g. They also have some higher bounce plates (hi-temp) that can be off by a few pounds.
I only know this because I read an independent review which I can't find the link to right now, where the guy went through and weighed all the plates he had. The hi-temps were useful for outdoor lifting, but had a significant variance, and on the heavier plates were as much as a couple pounds. This was in contrast to both the higher priced competition rogue plates and the Pendlay plates from muscle driver which he also had in his possession.
Some brands are legendary such as Eleiko, but you do get what you pay for. High price, great construction, and within very tight tolerances.
You don't have to get them IWF certified (which adds cost due to independent testing), but do look for the tolerance spec when reviewing the advertised plates.