T316 is a slightly higher grade of stainless steel that is suitable for use in marine situations.  It has similar characteristics to T304 in that it can be machined and welded relatively easily and is stable across a wide range of temperatures.  T316 is stable in saline conditions which makes it suitable for saltwater conditions and where the material is likely to come into contact with chlorides.
It can be bright polished to a high standard which means it is useful in a wide range of situations especially where aesthetics are important.

Bright polished tube comes with a mirror like finish which is ideal in circumstances where the finish is as important as the functionality. There is no compromise with regards the properties of the tube and can just as easily be welded and cold-formed but it will look even better.

Thin wall material is suitable when weight is premium, or heat conduction is important.  Thin walled tube will still be strong but not as strong as regular walled tube.  It is ideal for lightweight applications and small diameter tube.