You're looking at a process called extrude honing ... And to put his definition in simple terms; extrude honing forces abrasive material through metal passages via hydraulic pressure.

You realign the microscopic teeth on the blade's edge using honing steel. This process is quick and easy ... In contrast, sharpening entails removing material from the blade, which creates a ...

All-digital, servo-stroke honing for prototype to production volumes.