Precautions in use
Mechanical pencils ：How to handle lead leftover
The structure of the mechanical pencil is that the tip pipe and the chuck that feeds the core are separated, so if the core becomes short and comes off from the chuck, it gets loose because it is not firmly held.
There is an average of 10mm to 20mm of leftover parts per lead. If the lead does not come out by knocking, continuing knocking or drag the end of lead to pull out the leftover.