Glossary

Alloy, Carbon Steel - an alloy of carbon and iron containing a maximum of 2 % carbon, 1.65 % manganese, and residual quantities of other elements, except those intentionally added in specific quantities for de-oxidation (usually silicon and/or aluminum).

Alloy, Corrosion Resistance – a nonferrous-based alloy where any one or the sum of the specified amount of the following elements exceeds 50 %: titanium, nickel, cobalt, chromium, and molybdenum.

Backwall or Pipe Heel - the outer half or the half of the pipe undergoing tension during bending (see Extrados).

Base Metal – the metal or alloy that is welded, brazed, or cut.

Casing - a pipe used in wells to seal off the borehole; ordinarily is considered a fixed or permanent installation. (See tubing.)

Center-line Radius – is the same as bend radius.

‘D’ of Bend – is the center-line radius (CLR) divided by the tube diameter (CLR/D) or nominal pipe size, expressed like1.5D, 3D, 5D, etc.

Degree of Bend (DOB) - the angle expressed in number of degrees to which the bend is formed (45°, 90°).

Drop-Weight Tear Test (DWTT) - a test designed to determine the fracture toughness of line pipe.

Call 1-888-611-3976, contact us or fill out our Quick RFQ form and get reliable, trustworthy results on your next project.

Elongation – is (1) The increase in length of a test specimen in a tensile test, expressed as a percentage of the original length. (2) The increase in length of material fibers during bending.

Face, Weld – the exposed area of a weld on the side from which welding was done.

Filler Metal – the metal or alloy to be added in making a welded, brazed, or soldered joint.

Gauge - the wall thickness for tubes.

HAZ - (Heat Affected Zone) that portion of the base metal which has not been melted, but whose mechanical properties or microstructure has been altered by the heat of welding or cutting.

Induction Bending - a method or process of bending which utilizes an induction heating coil to create a narrow, circumferential, heated band around the material to be bent. When the appropriate temperature is reached the material is moved forward through the coil at a predetermined speed while a bending moment is applied. After the material passes through the coil it may be cooled (quenched) by air or water spray.

Longitudinal - the lengthwise axis of the specimen that is parallel to the direction of the greatest extension of the steel during rolling or forging.

Macrograph – a graphic reproduction of an object, slightly reduced in size, unmagnified, or magnified ten diameters or less (photo macrograph).

Neutral Axis - that portion of the pipe or tube that is neither in compression nor tension.

Optical (Spark) Emission Spectroscopy (OES) – a technique that utilizes a high energy spark created across an argon-filled gap between an electrode and a sample of the material to be analyzed. The spark creates an emission of radiation from the excited sample surface with wavelengths characteristic of the elemental composition.

P-Number - in order to reduce the number of welding procedure qualifications required, P-Numbers (P-1, P-2…) are assigned to base metals on characteristics such as composition, weld-ability, and mechanical properties; and for steel and steel alloys (Table QW/QB-422, ASME IX) Groups Numbers are assigned in addition to P-Numbers.

Quality Assurance – the activity of providing, to all concerned, the evidence needed to establish confidence that the quality function is being performed adequately.

Reduction of Area – the difference between the original cross-sectional area of a tension test specimen and the area of the smallest cross section. The reduction of area is usually expressed as a percentage of the original cross-sectional area. (The term reduction of area when applied to metals generally means measurement after fracture; when applied to plastics and elastomers, measurement at fracture.)

Sampling – is a defined procedure whereby a part of a substance, material or product is taken to provide for testing or calibration of a representative sample of the whole. Sampling may also be required by an appropriate specification for which the substance, material or product is to be tested or calibrated. In certain cases, the sample may not be representative but is determined by availability.

Tangent - the straight section of material on either side of the arc or a bend.

Validation – is the confirmation by examination and the provision of objective evidence that the particular requirements for a specific intended use are fulfilled.

Wall Thickness – is the thickness of the material, usually stated in “schedule” for pipes or “gauge” for tubes.

Yield Point – is the point at which the material will deform permanently during bending.

Call 1-888-611-3976, contact us or fill out our Quick RFQ form and get reliable, trustworthy results on your next project.