Sharpening the knives is essential for the cooks or chefs as after number of uses blades of the knives become blunt. Knives with blunt blade takes time in cuttings and cuts irregularly and can spoil the meat or veggies.
In Japan and Europe the process of the sharpening is different. however the most important key in sharpening is maintain same angle with each strokes which is in between 17 to 20 degree that helps in blade to be sharp at same angle from all side.
