ultimate tensile strength—the maximum stress that a material can sustain without failing from tensile overload.
ultrahigh-pressure water jetting—water jetting performed at pressures above 210 MPa (30,000 psig).
under film corrosion—see filiform corrosion.
uniform corrosion—corrosion that proceeds at exactly the same rate over the surface of a material. (This is the assumption when calculating corrosion rate or corrosion loss from mass loss or electro-chemical measurements. This term should not be used instead of general corrosion to describe an observed surface distribution of corrosion).
upset—a hotdeformation process to cause a thickening of metal by compressive forces.
urethane—not a preferred term, but commonly used to refer to polyurethane.