The nib, which can be said to be the most critical part of the pen, varies in thickness. Generally speaking, the most common pen tip sizes are "B (wide), M (medium), FM (thin-medium), F (thin) and EF (extra thin)". Extended data nib size difference:

The size of the nib will be slightly different from one pen factory to another in terms of specifications. Under the same size unit, the Japanese pen will be thinner than the European pen.

According to the usual writing habits, westerners usually use the M-tip as the main pen and choose the B-tip when signing. Due to the complexity of Chinese writing strokes, F or thinner EF pen tips can generally be used.

The width of EF=XF=Extra Fine pen tip is about 0.24 mm ~ 0.28 mm

F =' width of fine pen tip: 0.28mm ~ 0.34mm..

M = M = medium pen tip width: 0.34 mm ~ 0.44 mm

B = width B = wide nib: 0.44 mm ~ 0.54 mm

BB = The width of the double-wide nib is about 0.66 mm ~ 0.86 mm.