Carbon- Chemical symbol C, is an abundant non-metallic element.  As an alloying element it promotes austenitic structure, whilst also increasing mechanical strength.  Carbon reduce resisitance to intergranular corrosion, and in ferritic steels can reduce both toughness and corrosion resistance.

Carbon Steel- a steel whose characteristics are determined by the level of carbon content it has.

Casting- a manufacturing process whereby molten metal is poured/injected into a mould to form a required shape. See also spun-castings

Charpy Impact Test- also known as a charpy v-notch test,  this test determines the energy absorbed by a material during fracture.  A pendulum axe swings at a notched sample of material, energy transferred to the material can be inferred from the height of the hammer before and after fracture in the material.  The results give an indication to a materials toughness.

Chloride Stress Corrosion Cracking (CSCC)- cracking due to tensile stress and corrosion in presence of water and chlorides

Chromium- Chemical symbol, Cr, a grayish white, crystalline metallic element, with good hardness and high resistance to corrosion.    As an alloying element Chromium can increases resistance to wear and abrasion used in conjunction with carbon.  Commonly used in many stainless steels.

Cladding- a metal coating bonded to another metal under high pressure and temperature

CNC- Computer Numerical Control

Cobalt- Chemical symbol Co, Cobalt is a ferromagnetic silver white metallic element.  It is normall only used as an alloying element in marstenitic steels, where it's addition increases hardness and tempering resistance.

Coefficient of Thermal Expansion (CTE)- This is the change in density occuring as a material changes in temperature.  Metals typically increase in volume and decrease in density as it is heated.

Cold Drawing- A process whereby start stock is drawn through a die at room temperature to reduce diameter and increase length, commonly producing bar, rod or tube.  Allows close control of dimensional accuracy and physical properties.

Cold Working- the forcing of material into different shapes at room temperature.  This can be cold rolling, cold drawing, deep drawing or pressing.  Cold working decreases the malleability and ductility of material, which is then considered to be work hardened.

Columbium- Chemical symbol Nb, known now as Niobum, is a silver coloured ductile metallic element.  It is added in austenitic steels to improve resistance to intergranular corrosion.  It's presence in martensitic steels lowers hardness and increases tempering resistance.

Corrosion- The chemical or electrochemical reaction between a metal and it's environment (oxidation) which causes a deterioration in the metal and it's properties.