Accurate plate weight measurement/fractional plates

[Stevo]

Coach Rip,

Quick question about the accuracy of plate weight measurements & the importance of balance with barbell training...this was written about in SS:BBT but I didn't really think about until looking to buy fractional plates.

The site is http://www.fractionalplates.com/ & they refer to their products being accurate & then talk about questioning the accuracy of the plates from other vendors.

Regardless, I train at a local Y & they have rubber-coated Ivanko plates. Most are beat up & I started thinking about the accuracy of them. Should this be a concern? Short of weighing the damn things before using them, I don't think it's a big deal but I'd like to see what you think.

Thanks!
Stevo

[Mark Rippetoe]

If there is a scale, what is wrong with weighing them? How else will you know? You only have to weight them once and mark them. But then you have to make sure the scale is calibrated, which you can do with a pair of 45 lb. or 20 kg. plates that you know are milled to precision. You know this when you see the mill marks on the casting, or if you have contest bumper plates.