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.
An eardrum perforation is a hole or opening in an otherwise intact eardrum. The size of the perforation can vary from a small pinpoint opening to a loss of the entire eardrum. How does a perforation of the eardrum occur? There are many ways an eardrum perforation can occur. An infection behind the eardrum in the middle ear may cause a rupture of the eardrum. Trauma to the ear may result from an object entering the ear canal and puncturing the eardrum. A traumatic blow to the ear with a ...