"I see. I use a plumbers propane torch. Can you get small tips for those?"
It is a different system. Papa is talking Oxy/fuel torches that mix pure oxygen with the fuel gas before the mix exits the nozzle and is ignited. Tip size controls the size of the stream of mixed gasses that exits the torch, and therefor is one element in controlling how much heat one is using. Other elements, include the fuel gas, the mix with oxygen, the total pressure, etc...
You are probably using a naturaly aspirated jet ejector burner. Most of these use a nozzle that is burried in a tube where the mix with atmospheric air occurs. With these burners the fuel gas is propelled through the nozzle, where it mixes in the tube with atmospheric air and 4-10 inches latter there is ignition in the burner flair. There are examples of this type of burner that do have accessory burnner tips that can be inserted into the burner, but they are not used in the readily available commercial torches, and tend to require a large tank like those that come with a BBQ.