-edible zone-
The SME knife edge bearing
An after-market bronze knife edge saddle procured from an ebay seller in Taiwan:
(click thumbnail for full size image)
For comparison, a close-up detail of the SME manufactured steel knife edge saddle
Above image. Shows linear distances traveled as the knife edge bearing rotates. The bronze saddle with the wider flat moves a greater distance both vertically and laterally as the bearing rotates.