Stainless Pipe 304 Schedule 40 offers a great mix of strength and corrosion resistance in most situations outside of marine environments.
This is the most popular stainless alloy in the world, maintains its properties in high temperature situations. It is typically used in aerospace, food and beverage industry, pressure containers, architectural designs and trim, cryogenic applications, and chemical processing equipment.
The pipe is unthreaded to allow for welded connections.
Pipe is designed to carry liquid/gas/material from one place to another, whereas tube is designed to act as structural support.