Product Material Specification
Most of the clamps and components are cast from malleable iron, the material itself being manufactured to ASTM A47-90 (rev. 1995). Malleable irons possess good tensile strengths with high proof stress to tensile strength ratios and have substantial ductility and shock resistance. The stress / strain curve of the material indicates a constant modulus of elasticity but shows no yield point as in the case of a low carbon steel. Instead, the stress / strain curve is continuous with the onset of permanent deformation.
Malleable Iron is more resistant to atmospheric corrosion than ordinary steels, especially in salt air environments and it has greater rust resisting properties than other ferrous materials.
It was found that by adding magnesium to cast iron before pouring caused the graphite to form nodules rather than flakes. The composition of S.G Iron varies little to that of Grey Iron, yet it offers both ductility and increased strength. The reason lies in its microstructure (Nodular Iron), which refers to the formation of graphite spheres or nodules rather than flakes. The flakes whilst giving grey iron its unique properties are detrimental to its mechanical strength, breaking up the continuity of the metallic matrix preventing ductility. SG Iron is manufactured to the European Standard EN 1563:1997 grade EN-GJS-600-3, it has excellent corrosion resistance when compared to other ferrous metals and the free graphite in the structure also lends itself to ease of machining.
Mild steel generally falls into two groups, namely round bar made to BS970 Part1:1991, and flat and rolled strip or plate made to BS EN 10025:1990 and A1:1993
Stainless steel is a name encompassing a group of corrosion resisting steels containing 12% or more of chromium. The corrosion resistance of stainless steels is due to a submicroscopic film of oxides of chromium on the surface of the metal. If broken or damaged, this film instantly reforms providing oxygen is present and hence protects the underlying metal.
Stainless steels can be put into three classes, namely Martensitic, Ferritic and Austenitic. Often known as the 18/8 stainless steels, the Austenitic range of stainless steel is the most widely used. The designation 18/8 is from the 18% chrome and 8% nickel content of the steel, giving a higher corrosion resistance compared with normal chromium alloys. Austenitic stainless steels are non-magnetic.