How To Tell How Sharp A Knife Is?

Sharp Pebble Knife Cutting Lemon

What entails sharpness?

It’s obvious that a sharp knife is more reliable than a dull knife. One should understand what an edge is so as to gauge a blade’s sharpness. Basically, the line that intersects the two surfaces is what is known as the edge. Sharpening entails the process of making the blade’s edge fine. Therefore, a knife’s edge is referred to highly sharpened when the edge becomes very fine after highly polishing the two blade’s surfaces.

Testing the knife

Numerous ways exist for testing the sharpness of tools and knives. On our part, using the knife or tool itself is the easiest way to test its sharpness. A chef should be able to cut vegetables using a kitchen knife without any pressure. Otherwise, if the cutting process is not smooth and fast, the knife needs to be sharpened. Likewise, wood fibers need to be cut cleanly using a woodworking tool without either crushing woods fibers or leaving marks on the wood. In case it is cutting a fillet, a skinning or fillet knife cut the meat very quickly without sawing in it.

A paper test

Several other tests exist for a knife owner who wants to explore sharpness to its finest levels. One of the quickest ways is through utilizing a standard piece of paper. Hold the piece of paper vertically and try cutting it with the knife you are testing. When a knife is dull, it will either rip the paper unevenly or crumple the paper beneath the blade. If it is a sharp enough knife, it will cleanly cut the paper in a downward slicing motion. Whereas, if it’s a razor sharp knife there will not be slicing when the paper is cleanly cut as you gently press down on the paper’s edge.

Arms Hair test

Though not efficient, shaving the arms hair can be another effective way of testing a blade’s sharpness. However, caution should be taken when using this test since it is dangerous and prone to an accident as you run the knife about the arm. A dull knife will not cut but fold over the hairs of the arm. A knife that is well sharpened will trim a large portion of the arm hair at one instance. Whereas, when the knife is very sharp it will cut almost every hair that it comes across. It is also good to remember that only finest abrasive materials can attain this sharpness level. 

What to note about sharpness

Apart from the sharpness of the edge, the angle at which a blade it sharpened will affect its sharpness level. The blade becomes sharper as the angle lowers. Detrimentally, the edge also becomes weaker as the angle reduces. That is why a fillet knife or a razor blade where its angle is very low have sharper edges compared to axes which have high angles. However, such sharp edges will need frequent sharpening since its edges do not last long enough.