Generic terms

Sandblasting
It is generally perceived by the users as being the "air blast" shot technique of a material on a part, whatever the nature of the abrasive is. This inappropriate term comes from the first steps of this technique which is very used in the shipbuilding industry, in the building industry and in the civil engineering. Formerly, this technique used the sand now forbidden.

Shot-blasting
It is perceived by the manufacturers and the professional experts as being the basic projection principle of a metallic material on the parts to treat. This term is often understood in its more restrictive sense and it excludes the other materials such as minerals, vegetal abrasives, synthetic ones, as well as the compressed air projection systems and other gaseous vectors. It is often compared to the "blastwheel" projection but on the contrary, it includes for the manufacturers all the projection systems and all the kind of projected materials.

Stripping
This term is perceived almost exclusively as a chemical stripping in opposition to the mechanical processes of shot-blasting and sandblasting. However, the manufacturers mean by this term all the chemical or mechanical processes intended to remove the calamine or the rust from the surface of a part.

The surface treatment
This term is an object of great confusion. For most manufacturers, the surface treatment covers a nobler activity than shot-blasting, such as the plating or the enamelling whereas it includes actually any operation relative to the modification of a surface: stripping, peen forming, shot peening, etc. This more global term is more appropriate.

The surface finish
A surface finish is the way of being of a body external part. This is the limit between two different physical environments. Any body is the result of transformations, matter treatments that will alter or modify more or less its surface with the possible apparition of contaminated agents which will have to be eliminated. Therefore its surface finish can be progressive. It is important that its final state corresponds to the characteristics of the functions for which it has been created initially.
These characteristics depend on:
- the man (sight, touch)
- elements (air, water)
- machines (resistance, friction)
Therefore, the surface finish is a whole of different chemical, physicochemical, microgeometrical and crystallographical characteristics. The four major ones are:
- appearance: aspect, presentation and control quality
- the care degree: graduation of contaminated agents elimination that modifies the aspect and the colour.
- roughness: state created or modified to ensure the adhesion or fixing qualities of protection products and coatings, or facilitate the friction qualities on mechanical parts.
- hardness: quality of the surface stresses which can be modified with a work hardening treatment or "shot peening".

Search for a surface finish
It turns towards three main functions:
- cleaning: it means to eliminate any contaminated agent, coating or degraded protection of a surface.
- preparing: it means to create a roughness allowing the fixing of a coating or a later deposit.
- modifying: it means to bring surface stresses which improve the mechanical resistance.