Methods of Testing a knife for sharpness

Having a sharp knife is an ideal for everyone. It can be somehow tricky to measure a knife sharpness, but before going there it is very important to understand what a knife-edge is? A knife-edge is simply the sharp part of the knife that is mostly used for cutting. So, a sharp edge means a sharp knife. There are many ways of testing a knife sharpness but the simplest way is using the knife and see how it performs. A sharp knife can cut many things easily and effortlessly. The following are some methods that can be used to test a knife sharpness:

1. Arm hair Test

This is one of the easiest and most accurate methods of testing whether your knife is sharp or blunt. This method can be dangerous so, you need to be more careful. This method involves cutting your arm hair using the knife. Because the hair is very thin, it can be hard to cut. If you pass the knife along your arm and it leaves less or no hair then your knife is sharp. But if the knife leaves most hair uncut, then something needs to be done.


2. Slice an onion

This is an effective method especially for testing kitchen knives. Since onions are slippery and thin skin, this trick can be perfect. How do you go about this? It is very simple. Pick your onion, then slice it by using your knife. A sharp knife will easily slice the onion without necessarily applying a lot of pressure. On the contrary, a blunt knife will need a lot of force in order to slice an onion. Apart from an onion, you can test this by using other things like tomatoes, potatoes, meat or vegetables among others.

3. Fingernail Test

This test involves using your fingernail. It is very simple and accurate. A fingernail is relatively hard and this makes it effective for the test. It is also easy to perform this test. What you need to do is place the edge of the knife alongside your fingernail, ensure that the blade is in a perpendicular position, then try cutting your nail. If the edge of the knife slides, this means that the knife is dull. On the other hand if the remains in place, it actually means that your knife is ready for working. You need to be extra cautious when carrying this test. You will not want to hurt yourself.

4. Use your finger

Yes, you can as well use your finger to check for a knife ‘s ability to cut. This tip does not involve complicated procedure but if not well-used, it can be very dangerous. So, you need to be more than careful. Just pick your knife and feel its edge with your finger. The smoother the edge, the sharper the knife. But when you feel rough edges, it actually means your knife needs to be sharpened. This trick can also be used to check the edges which requires sharpening.


5. Slicing paper Test

Pick a piece of paper and place it in a vertical position. Take your knife and keep in mind to use the entire edge. A dull knife will make it hard to slice the paper. It will also leave irregular shaped and torn papers. But if the paper remains clean and you did not struggle, you should be happy. This actually means some great news. That your blade is great for working. This tip can also be used to check the dull sections. Another great way of checking knife sharpness, is using magazine and phone book papers. Both of these papers are very thin and might be hard to cut. So, if your knife is capable of slicing these papers without you necessarily applying some efforts, then we can say that your knife is very safe.


6. Try hard-to-cut substances

This is a great way to test woodworking knives. Try to cut difficult substances like clipboard, wood, sugarcane or even meat. If the knife penetrates on a difficult substrate, then you are lucky. The above are some best ways which you can use to test whether your knife is sharp enough. Some methods are a little dangerous. So, one needs to be careful.