These are hundreds of different soldering iron bits in sri lanka. The most common is the conical tip, single flat type, which is used in most 35 to 100 watt electronic soldering irons. Above 100 watt soldering irons sometimes use bevel tips the large surface holds more lead than other soldering bit types. These are used for soldering multiple selections of pins or surfaces at once. Conical tips are used in electronics for its precision. The focused tip can easily solder a required small areas.