A nib grade can vary from manufacturer to manufacturer, and to make it even more confusing, the actual writing width can vary from nib to nib. Higher end nibs are often finished by hand, and unless each is measured precisely, they will be different.
They all look like mediums, roughly, but when you really start looking and writing with them, some are more wet, some are softer, some are wider, some offer more line variation. This is why it’s really fun to try out a pen before you buy it!
