EV Anvil (exhaust valve)

[Frank S]

Ed. I'll offer an explanation which may be of use to others as well. Any hard object becomes an anvil when another object is placed or laid on it and struck with a 3rd object the 3rd object becomes a hammer regardless of shape or weight this is also true of an anvil. A person could place a nut on any surface then strike it with their fist the surface is the anvil and the fist is the hammer
I often use the counter weight on my forklift as an anvil when I need a very large hard surface to assist in shaping sheet metal also I often use 2 hammers by holding 1 as a back up while striking with the other the back up hammer is at that instance an anvil.
If the object being used as an anvil also has a particular shape that something is formed into over or around then it could be called a die as well
LMMasterMariner's use of a large diameter exhaust valve is just one more example of the many things which can be utilized as beneficial simple tools readily at hand