I've noticed that alot of people have had problems getting the nipples to screw into pipes, buckets etc. Maybe others have noticed this too, but I haven't found it in threads so I apologize for repeating if someone else has posted this. When I bought some nipples to put in a bucket, I thought that the size and thread pattern looked familiar. Sure enough, it is exactly the same size as the hardware that lamps and lighting fixtures use. Instead of drilling your hole into the bucket a little too small and then trying to screw the nipple in, you can make the hole large enough for the threads to easily fit (3/8"), and then just put a nut from a light fixture on the back side of it. Fits perfectly!! A tiny dab of silicone on the threads doesn't hurt anything either. If you don't have old fixtures laying around, you can usually buy the nuts (cheap) at Home Depot or most hardware stores in the electrical department. Sometimes, you can even find them in solid brass if you're worried about them rusting. Hope this helps!!