That is steel strips cut from steel plate with a cold saw.
I know it's pricy, I prefer to buy from Speedy Metals or On Line Metals over buying from some of the sellers on eBay. If they don't show a real picture of what you are buying, it can be shady and the results poor!!!
And there is a ASTM/ANSI/ASME standard that controls tolerances of cold drawin or hot rolled steel products. And that may not meet the requirements of the standard. But the tolerances is also controlled by the type of processing used and what you received MAY meet one of these requirements.