knife-edge

Use a light touch, slope the knifeblade and slice with knife edge away from you (Figure 1).

He had hunted mountain sheep and imagined sun and frost had worn the rocks to something like a knife-edge.

In the heights are numerous ledges and knife-edge ridges on which but little snow can lodge.

This ruby pin acts on a knife edge, but for all that the engaging friction during the unlocking action is considerable.

The knife-edge is then turned forward and made to cut its way out.