Its a good question,let me answer your question.
There are many kinds of metal filter element,but I think the wedge wire screen is the best choice ,its also called johnson screen.
Wedge wire screen consists of surface profiles, usually V-shaped, that are resistance welded onto support profiles. The distance between the surface profiles is controlled very accurately, as it forms the slot through which the filtrate flows.its advantages are as follows
1. V-shaped slot formed,non-clogging.
2. High filtering performance.
3. Material is stainless steel or duplex stainless steel ,have good corrosion resistance.
4. Strong construction
5. High open area
6. Accurate slot dimension
7. Easy to clean,long service life,safe and reliable,low comprehensive cost.
8. Low pressure-drop
So the wedge wire screen is the best metal filter element for the water treatment ,many people called it water treatment filter.
If you want to know more about wedge wire screen,you can check:Wedge Wire Screen/Johnson Screen. This is a very professional website for wedge wire screen manufacturers,you can ask any question on it ,and you'll get a professional reply soon.