Chances are, if you are refurbishing an old bike, you have an adjustable cup and cone square taper bottom bracket. Unlike contemporary sealed bearing bottom brackets, these older units need two things: occasional repacking of the bearings and adjusting of the bearing preload. Both are doable, and if you want to keep the serviceable bottom bracket rather than getting a sealed bearing unit, go for it. You need this tool, plus a square taper crank puller and a lock ring wrench. This tool will let you adjust the actual cups of most non-sealed bottom brackets. Shimano, Sugino, etc. I can’t tell you if it will work on some old Mavic unit or a 1943 stronglight bottom bracket. Probably not.
Made by Unior in the EU.