1. electric grinder: electric grinder uses grinding wheel to produce high-speed grinding, which can sharpen tools quickly. There are two common types: angle grinder and circular grinder. Its advantages are high grinding speed and good grinding effect. The disadvantage is that the price is high, which is easy to cause excessive grinding and ultra-high temperature damage of tools.

2. Hand grindstone: such as oilstone and water stone. Slowly grind and trim tools by manual friction. Its advantages are low cost and not easy to damage the cutter. The disadvantage is that the grinding speed is slow, and the grinding quality depends on personal technology.

In addition, there are polishing powder, abrasive belt grinding wheel and folding pocket grinding wheel. Each has its own characteristics.

So which of these tools has a better sharpening effect? My suggestions are as follows:

1. For home use, especially for people who have just started sharpening their knives, it is recommended to sharpen them manually. Because it is simple to operate, low in price, not easy to damage tools and relatively safe. You can start with coarse-grained stones and gradually gain skills, and then use fine-grained high-grade stones. This is the most traditional and gentle way to sharpen the knife, which is very suitable for getting started.

2. If you want to polish quickly and efficiently, an electric grinder is also a good choice. However, we must choose products with moderate rotation speed, and keep pouring cooling water to avoid overheating and damaging the tool. At the same time, the grinding time and intensity should be controlled to prevent excessive grinding. This requires some skills and experience, so the electric grinder is more suitable for users with a certain foundation.

3. For those who pursue high precision and mirror polishing effect, polishing powder and high-grade water stone or oilstone will be more useful. But it requires a lot of skill and patience, and it is not recommended for ordinary families.

To sum up, for ordinary families, I would recommend handmade oilstone or water stone. Its ease of use and gentleness are more suitable for novices to grind daily knives. Electric grinder is also a good choice, but we must pay attention to the use method and strength to prevent accidental injury of tools. Polishing powder and high-grade stone are more suitable for professionals.

Manual grindstone and electric grinder are two practical sharpening tools with high cost performance. Either one can meet the needs of the household well. I hope this suggestion will help you.