what tools are used to sharpen knives?
['Sharpening Stone or Whetstone. | The whetstone is probably the most popular knife sharpening tool used. ... ', 'Sandpaper. | ... ', 'Sharpening Steel. | ... ', 'Knife Hone. | ... ', 'Electric Knife Sharpeners. | ... ', 'Handheld Sharpener. | ... ', 'Serrated Knife Sharpener. |']