Eccentricity of Tubing - Variation on wall thickness, when the wall is lighter on one side and heavier at a point 180° away, resulting in the I.D. of the tube being not concentric with the O.D.
Eddy-Current Test - Nondestructive testing method in which an eddy-current flow is induced in the test object. Changes in the flow caused by variations in the object are reflected into a nearby coil or coils for subsequent analysis by suitable instrumentation and techniques.
Edge Condition - Mill Edge: Normal edge produced in rolling, conforms to no definite contour. Sheared Edge: one cut after rolling. Slit Edge: produced when strip or coil is slit into multiple widths.
Elastic Limit - The maximum load per unit of area (usually stated as pounds per square inch) that may be applied without producing permanent deformation. It is common practice to apply the load at a constant rate of increase and also measure the increase of length of the specimen at uniform load increments. The point at which the increase in length of the specimen ceases to bear a constant ratio to the increase in load, is called the proportional limit. The elastic limit will usually be equal to or slightly higher than the proportional limit.
Elongation - The increase in length of a test specimen after rupture in a tensile test, expressed as a percentage of the original length.
Endurance Limit - Maximum dynamic stress to which material may be submitted for an infinite number of times without causing fatigue failure.
Etch Tests - Etching to detect inclusions in steel. A common test is dipping a sample into acid which reacts with the inclusions to disclose their presence.
Etching - Revealing structural details by preferential attack of reagents on a metal surface.
Eutectoid Steel - Carbon steel with a 100 percent pearlite structure, which is the structure developed under normal conditions of hot working and cooling when the proportion of carbon is about .80 percent. Hyper-eutectoid steel has a greater percentage of carbon, and Hypo-eutectoid steel has less carbon.
Extensometer - An instrument for measuring changes caused by stress in a linear dimension of a body.
Extruding - Shaping metal in continuous form by forcing it through a die.