I have been looking for a solder tip but after buying one at radio shack then returning it because it was too big, stopping at two stores and calling a third one I have not found one that works. I would prefer to not pay a large shipping fee, one or two dollars at most but free shipping would be much preferred. I have a Weller SP23 and it's 23 watt (it also has another number on it that says 336B.) Does anyone have any recommendations on retailers?