One of the first nine metal valves was the 6F6 output pentode, soon after the first 6L6 was produced and then the 6V6.  Glass equivalents of these were manufactured in the US, Canada and Europe.  Today these glass types are still made in China and Russia.  The original metal types were never manufactured in Europe, though the US tubes were sometimes resold under British brands.

6A8	Replaces 6L7 but 6K8  soon replaces.
6V6
6L6		photo
6N7	QPP dual output triode
6Q7
6R7
6J5		photo
5W4
5T4

Later types. The 6S.. types replaced those with top connections.