Outside diameter of core tube: about 4.5mm.

The length of the core tube is 1 10mm in Korea and10mm and15mm in China. ..

Outside diameter of flange: about 6.5mm.

The inner diameter of the pen mouth (the part where the gel pen tip is clamped) is about 2.5 mm, and the tip of the pen may be slightly thinner.

Length from the flange (the part clamped by the pen nozzle for fixing) to the pen tip: about15 mm.

The total length of the refill (from the end of the refill to the nib): 130mm is mostly made in China.

Extended data:

Written type

First, the bullet type.

If we look closely at the tips of these gel pens, we will find that they are just like bullets. In the manufacturing process, we cut an original rod into a complete nib by metal cutting. The bullet type is suitable for making thicker pens, which are mostly 0.5MM in the market, and the thickest one can reach 1.2.

Second, the needle type

This pen is usually called a "full needle tube". The key difference between it and the bullet pen is that it is processed by non-cutting method. Before it is processed into a pen tip, it is a complete thin tube, and three concave points are punched out at the front end of the thin tube from three directions with precision instruments to form the bowl seat of the ball; The thin tube at the back forms a triangular oil groove.

Three and a half needles

The semi-needle tube is between the bullet and the needle tube, and the appearance is more beautiful. The nib can be as thin as a needle tube and the tail can be as big as a bullet. The semi-needle tube type can be used as a thinner pen tip, such as 0.48, 0.35 and so on.

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