As we all know, because primary school students just go to school, "typos" and "miscalculations" are inevitable, so teachers in lower grades of primary schools generally require pencils that can erase handwriting. Generally, pencils are sharpened with a pencil sharpener or pencil sharpener, and then students use it to write. When primary school students write hard, if the writing strength is not well controlled, the nib will break. I had to cut again after I broke it. Even if you write normally, because the commonly used HB pencil wears away quickly, it is cut without writing a few words. According to incomplete statistics, the lead of a standard HB pencil really used for writing only accounts for 30% of the total volume of the pencil, and all other wooden poles are wasted. Some people may say that mechanical mechanical pencil can be used, but the commonly used 0.5mm or 0.2mm automatic lead will break with a little force, which is not suitable for the lower grades of primary schools. For the upper grades, it can only be used in some cases. Not only that, this automatic lead writing will have a rough and sluggish feeling, which is not very smooth. However, the "alloy core erasable pen" has almost no problem of breaking during normal writing, and writing is equivalent to a self-grinding process, which is very suitable for primary school students in lower grades.