What will you see when a very short pipe is threaded?

When a very short pipe is threaded, the correct outcome is the nipple chuck. A nipple chuck is a term used to refer to a short piece of pipe that has threads on both ends and is typically used to connect two other coupling fittings or piping. Since it is short, it can easily fit into tight spaces, making it a preferred choice for connections where length is minimal.

The other options would not apply in the same context as the nipple chuck. Packer couplings typically connect to larger pipes and can handle changes in direction or pressure, but they do not specifically describe a short threaded pipe. Half couplings are designed to connect a smaller pipe to a larger mainline, and an expansion coupling allows for movement in piping due to thermal expansion, but they do not specifically refer to short threaded pieces. Thus, the nipple chuck is the most appropriate choice when discussing very short threaded pipes.