Ef tip is the technical index of pen making, which has nothing to do with calligraphy. Ef sharp.

The difference between the two pen tip widths is as follows:

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

F = the width of the fine pen tip is about 0.28 mm ~ 0.34 mm

Extended data:

The nib is the soul of a pen. There is a lot of knowledge about the nib. A good nib is usually made of high-quality stainless steel or gold. Generally, it is 10K, 12K, 14K, 18K, 2 1K, but there are also 18K gold.

Pen tip materials can be roughly divided into three categories:

1, stainless steel nib,

2. Common golden tips: 14k, 18k, 2 1K, etc.

3. Pen tips made of other rare materials: palladium-silver alloy, titanium alloy, etc.

There are many reasons for the water output of the pen and the adhesion between the nib and the tongue, and the adhesion of the tongue interface ... Don't just nail water to the tip of the pen.

References:

Pen tip-Baidu Encyclopedia