Plating of the tip? Whether the treatment was not good, the oxidation was intense and it became difficult to use with a little use time after the electricity supply. It occurred in 1 book while buying 5 books.
After all, I have been using this for 20 years ago, but it is an item saying that there is only this if I get used to it. I think the matching angle with this soldering iron is amazing. From now on I will continue to use it.