Since 12L14 is an extraordinary machining steel it has become the favorite carbon metal for machining-especially on light weight lathes. It offers inherent ductility combined with finer surface quality. 12L14 has a smooth cold finish (rolled) surface.
1 An infection in the middle ear. When the middle ear is infected, pressure builds up and pushes against the eardrum and can cause the eardrum to perforate. When that happens, you may suddenly notice that the pain and pressure you've felt from the infection stops and pus drains from the ear.  An injury to the eardrum.
Fluid behind the eardrum is called serous otitis media. It can create pain and hearing difficulty similar to a middle ear infection. The eardrum can rupture (break) in severe cases of ear barotrauma, causing bleeding or leaking of fluid from the ear. A ruptured eardrum can result in hearing loss. In severe cases, it is possible for the pressure to create a leak between the deepest structures of the ear (the fluid-filled bony canals called the cochlea and semicircular canals) and the inner ear space.