A method of fitting a fastener to an object is introduced. The fastener has a weldable surface and an engaging portion or a hole portion. One end of the hole portion or one end of the engaging portion has a holding portion. During a welding heating process, solder flows into or enters the holding portion and then cools down and solidifies therein so as to be held therein. Therefore, the weldable surface and the holding portion together enable the fastener to be firmly coupled to an object. The engaging portion and the hole portion together enable an object to be coupled to or removed from another object, so as to couple together and separate at least two objects repeatedly and quickly.