I have several items from Sears, rolling tool chests, workbenches with drawers. These appear to be from Waterloo Industries, Sears source Code 706. The drawer slides have springs made from flat stock, two springs each slide, four springs per drawer. These serve to limit the travel of the slides and of the drawer in the slides. Sear sells these springs as M3163 for over $3.00 each. Waterloo sells them for $1.09 each (1-800-833-4405), using the same part number. I like Sears, but I also like to be able to purchase additional things within the limits of my income.
At some point, the shape and size of the springs changed a bit but I am assured that the newer version works just fine as a replacement for the older version.