The counterbore tool is typically a specialized drill bit that creates the hole for the body of the fastener and the larger sized cavity for its head, both at the same time. Usually, the fastener chosen is a flat-bottomed screw such as a round head or a pan head screw.sually, a socket wrench is used for the purpose, which means enough space must be available around the screw head to insert the socket wrench and allow it to grip the head of the fastener. For this, the counterbore cavity is drilled to a diameter larger than that necessary to accommodate the socket wrench.
An electrocardiogram (also called EKG or ECG) is a test that records the electrical activity of your heart through small electrode patches attached to the skin of your chest, arms, and legs. An EKG may be part of a routine physical exam or it may be used as a test for heart disease.
The EKG can provide important information about the patient's heart rhythm, a previous heart attack, increased thickness of heart muscle, signs of decreased oxygen delivery to the heart, and problems with conduction of the electrical current from one portion of the heart to another.