Name given to petroleum oils compounded with chemical addition agents to enhance certain properties such as detergency, antioxidant characteristics, etc. or any material added to a lubricating grease or lubricating oil to improve its suitability for service. It may improve a property already possessed by the lubricant, or give it properties not naturally possessed. Typical examples are antioxidants, EP agents or anti wear additives.

Adhesive Wear

Wear caused by metal-to-metal contact; characterised by local welding and tearing of the surface.


Any substance having basic properties (as contrasted with acid properties). In a restricted sense in grease manufacture, this term is applied to the hydroxides of the alkali metals, including lithium, sodium, calcium and other metal ions.


A substance having metallic properties, containing two or more chemical elements, at least one of which is metal. The substance usually has qualities different from those of the individual components.


Oxide of aluminium. Usually produced from bauxite as a first stage in the manufacture of aluminium. About two tons of alumina make one ton of metal. Also a refractory and an abrasive.


Used to deoxidize steel and control grain size with additions up to around 0.05 wt. percent. Grain size control is accomplished by the formation of a fine dispersion of aluminum nitride precipitates, which restricts austenite grain growth. Aluminum can be added at higher levels as an effective nitride former in nitriding steels.


A term applied to such materials as carbon black, as contrasted with such crystalline materials as graphite or Molybdenum Disulfide.

Anti – Foam Agent

An additive used to suppress the foaming tendency of petroleum products in
service. May be a silicone oil to break up surface bubbles or a polymer to decrease the number of small entrained bubbles.


Metallic deposits formed in the combustion chamber and other engine parts during high temperature operation


The independent evaluation of the physicochemical composition of a metal or alloy to determine its degree of purity. Also to establish the metal content of ore or scrap. Also international standards, and some standards peculiar to futures market contracts, specify metal contents and maximum levels of impurity. Metals and ores are assayed to establish if they meet these.

Bentonite Thickened Greases

A non-soap thickened grease that makes use of an inorganic powdered clay to absorb the base oil without the need of chemical reactions or shear. They have a wide operating temperature range and very good water resistance. They are said to have no droppoint. Bentone is a trade name.


An aromatic hydrocarbon used as an intermediate and as a solvent. Benzene is a toxic substance.


A solid semifinished round or square that has been hot worked usually smaller than a bloom. Also, a general term for wrought starting stock for forgings or extrusions.


Used in certain steels to control the composition, type, shape, size and distribution of oxide and/or sulfide inclusions. Ca can also be added to improve castability.


A compound of carbon with one or more metallic elements.

Carbon Steel

Ordinary unalloyed steel.


An element or compound which facilitates a chemical reaction without itself being consumed or altered. Classic examples are platinum in oil refining or Raney nickel in edible oils manufacture. Automotive catalysts are an important application of precious metals to reduce exhaust gas emissions.


Used in alloy steels to increase

1) resistance to corrosion and oxidation

2) high temperature strength

3) hardenability

4) abrasion resistance in high carbon alloys


A ceramic pot or receptacle made of materials such as graphite or silicon carbide, with relatively high thermal conductivity, bonded with clay or carbon, and used in melting metals.

Crucible Furnace

A furnace that melts metals in a refractory crucible. The furnace is typically fueled with coke, oil, gas or electricity.


Formed by or characterized by heat reaction as in oxidation.


A process of heating a billet of metal to a plastic state and forcing it through a die. This enables the quick and economical production of long lengths of complicated sections. Lead was the first metal to be extruded, but today aluminium, brass, magnesium and even stainless steel are extruded.

Ferro Alloy

An alloy with iron of a metal used to make steel alloys. The ferro-alloy is more easily produced from the ore than the pure metal and may also be easier to add to the melt. Most ferro-alloys are used to add alloying elements and to treat or modify iron or steel. See also Master alloy.


Materials mainly containing the element iron, i.e. iron and steel.

Ferrous Metal

An alloy that has iron as the predominant metal.

Flash Furnace

A smelting furnace in which the concentrate and fuel are blown into a closed chamber in finely-divided form. A much faster reduction than in a reverberatory furnace.

Floor Molding

Making sand molds from loose or production patterns of such size that they cannot be satisfactorily handled on a bench or molding machine, the equipment being located on the floor during the entire operation of making the mold.

Fluid Friction

The internal friction of the lubricating oil film when the solid surfaces between
which relative motion is taking place and separated completely by a fluid film. Under such conditions,the oil flows in parallel layers like a pack of playing cards sliding over each other when the outside cards are held adhering to the palms of the hands and the palms are moved relatively to each other,thus causing the outside cards to move with the hands and the intervening cards to move in relation to their position in the pack.


Shaping steel and some non-ferrous metals while hot by repeated hammer blows. Forces of up to several tons may be used. Often results in the strongest form of the metal in the alloy used.


(i) Place where castings are made.

(ii) The last department in a smelter where the metal is cast into standard shapes (semis in steel). In copper (casting anodes) and aluminium (casting slab and billets) the department is usually known as the Casthouse


Devices for concentrating heat to achieve melting temperatures.


A strong alloy of 85% copper, 5% tin, 5% lead and 5% zinc, or near variant of this mix.


A casting of a simple shape that can be used for hot working or remelting.


The product of the smelting of iron ore and the raw material for steel.


Can be added to improve machinability. It does not dissolve in the steel matrix but remains as secondary particles. Environmental concerns are resulting in a decreased usage of lead in the steel industry.



A common alloying element used in most steels because it deoxidizes the melt, facilitates hot working of the steel by reducing the susceptibility to hot shortness due to sulfur content and adds to hardenability.


(i) The complex of crushers, ball mills and flotation cells that comprise a concentrator.

(ii) A rolling mill.

(iii) A metal-cutting machine that complements a lathe by producing flat surfaces, keyways etc.


Increases hardenability of steels and helps maintain a specified hardenability. It increases high temperature tensile and creep strengths. Molybdenum hardened steels require higher tempering temperatures for softening purposes.


Used in low alloy steels to reduce the sensitivity of the steel to variations in heat treatment and distortion and cracking on quenching. It also improves low temperature toughness and hardenability.

Non Ferrous

A negative term; refers to alloy in which the predominate metal or solvent is not iron.


Generally restricted to below 0.04 weight percent to minimize its detrimental effect on ductility and toughness. Certain steels may contain higher levels to enhance machinability, strength and/or atmospheric corrosion resistance.

Pig Iron

(i) A rough cast shape from the blast furnace, e.g. pig iron.

(ii) Also the standard form in which lead is traded internationally and delivered on the LME. See also sow.

Powder Metals

A distinct branch of metallurgy. Powder metals may be compacted and sintered to form finished components with particular characteristics, used in surface coating techniques or even burned in pyrotechnics.


Heat-resistant material, usually non-metallic, used for furnace linings etc.

Release Agent

A film applied to a mould contour to enable removal of a newly moulded
component while protecting mould and component finish.

Shot Blasting

A process for cleaning castings that involves using a metal abrasive that is propelled by centrifugal or air force.

Silica Sand

Sand with a minimum silica content of 95% used for forming casting molds.


One of the principal deoxidizers with the amount used dependent on the deoxidization practice. It slightly increases the strength of ferrite without a serious loss of ductility. In larger quantities, it aids the resistance to scaling up to 500°F in air and decreases magnetic hysteresis loss.


A film that forms on top of molten metal as a result of impurities. Slag is composed of non-metal elements.


The principal structural metal, made from iron. Less expensive than other metals and stronger than most, but heavy and prone to corrode unless protected.


Detrimental to transverse strength and impact resistance. It affects longitudinal properties to a lesser degree. Existing primarily in the form of manganese sulfide stringers, sulfur is typically added to improve machinability.


Inhibits grain growth during heat-treating while improving strength and toughness of hardened and tempered steels. Vanadium is also utilized in ferrite/pearlite micro-alloy steels to increase hardness through carbonitride precipitation strengthening of the matrix.