Valve seat question.

What material is the valve seat on a Commando ?, I have a Combat head, the valve seats are non magnetic. Is it unleaded fuel safe ?.

The Atlas head I pulled off the bike have magnetic valve seats.

Josh, I don't know what the exact material the valve seats are made of, but I do believe that the non-ferrous ones are a hardened stainless and I know they are very serviceable with a stock engine. If you change seats, I believe stellite is still the material to use. Change the ferrous (magnetic) ones for sure.

Mike

That is a curious question. Titanium? Tungsten? Platinum? nah. maybe a type of stainless? nah. There is quite a list of non magnetic metals that are tough enough to be valve seats. More than likely stellite. I believe it needs to be 35 to 45 on the rockwell to be tough enough yet allow for good seating in a no lead application.
I will be watching to read the expert answers.

Motorcycles and alloy heads (and Nortons) have been using quite hi-spec grades of valve seat inserts and valve steels for many decades now - since the early 1950s.
Be surprised if the seats or valves need changing at all for unleaded.

Bronze?

Not bronze.