[dogwood]

After my last post about dodgy steel,
I have just been looking on Parker steel site.

I've got a question about alloy flooring.
I used 2mm 5251 alloy plate.
On Parkers steel they are showing 2mm 5bar tread 5754 alloy plate

Assuming the 5bar tread is raised up.
Does anyone know if this is 2mm plus the tread thickness
or 2mm including the tread?
Also what is the difference between 5251 and 5754?

Cheers David