I was searching around and came across this link from Ted Pella:
Scroll down and you'll find:
Double edge, carbon steel blade
Sharp edges; may be broken in half lengthwise (protect fingers and use eye protection). This is the preferred razor blade for use with the Vibratome®, Microslicer™ and other vibrating microtomes.
Length: 42.8mm (1.685")
Cutting Edge Length: 36mm (1.42")
Width: 22mm (.865")
Thickness: .127mm (.005")
This surprised me! Any thoughts!?
I know there was interest in the Treet "Black Beauties" carbon steel blades about two years ago. I didn't know Feather made them. Anyone ever try em?