These blades (and dispenser springs) are degreased in order to minimize particulates and residual grinding oils on the blades. The blades are made from surgical stainless steel (significantly more durable then carbon steel) with a steel back that produces less particulate than the aluminum back type. Packed 10 blades per dispenser, 200 dispensers per case. The blade (including steel back) measures 39 mm x 19 mm x 0.23 mm thick (1½"x ¾ "x 0.009").