The usual tungsten barrel threads are called "2BA" which follows a British norm. Older brass darts often have a 1/4 inch thread, these two threads are not compatible. 1/4 inch threads are as ancient as brass darts are, so there usually is no need to worry about that when buying a tungsten dart. Standard shafts or soft/movable tips you buy are equipped with the 2BA thread, so problems with incompatibility of the threads should not occur.
However, there are some pitfalls. Some dart manufacturers supply darts with "alternative" attachment methods. The shaft of this kind of dart isn't attached with a tungsten dart threads, it is attached through just a thin whole and a rubber tube to fix it. This system is unique -- as good or as bad as the thread system, but you have to take into account that for shafts for this system you will have to rely on the manufacturer. For other companies supplying a shaft only for such special series is not economical.
The bottom line is, if you are buying a new dart take your old spare parts with you to see if you can use them on your new dart. If you buy your first strong dart set, try to attach the cheap standard spare parts of the shop to this dart, not the ones that are shipped with the darts when you open the box.
We appreciate very much to receive your particular designs, and always try all out to meet any specific requirement. The motto for our company is that, there never be minimum order, but any one could bring to us the most potential buyer.