I have a Delta kitchen faucent with a diverter shank that connects to a hose for a pullout sprayer. I am disconnecting it because I want to use the sprayer hole for a filtered water faucet. The problem is that the hose connects to the shank via a 5/16" fitting. I have disconnected the hose and need to find an end cap that will screw onto the shank.
I showed the hose to a plumber who happened to be at Home Depot (another customer, not a staff guy) and he says, "Oh, that's a standard 3/8" fitting", then I say, "No its 5/16th", then he says, "No such thing, its 3/8ths". Then we go over to the fittings and find a male 3/8" plug and sure enough its slightly too big for the hose. He's like "Damn, its 5/16th". So he directs me to a plumbing supply store. I go there. The guy is like "We have no 5/16th anything".
I have a lathe, do I need to get some hex rod and cut my own internal 5/16" diameter thread. I hope not because I hate cutting internal threads, especially into a blind hole. Please tell me there is somewhere I can get a 5/16" brass end cap. Note that an adapter will do just as well, because if I can get a 5/16" to 3/8" adapter, then I can use a 3/8" end cap, which Home Depot does have.