This is an iron without any British Standards and is a generic term for irons in their natural state as found in the ground. However, the British ore must have had a tendency towards being more heat resistant than imported ores and the name has become synonymous with heat resisting iron.Contact us01484 428203
Haematite is predominately used for furnace and oven parts such as doors, arches, jambs and sills.
Generally heat resistant iron alloy has 3.3 - 3.5% carbon appearing as graphite with a silicon content 2-2.3%. A quick hypothesis is, as the iron is heated it will expand 1mm in 120mm as it cools the contraction is the reverse.
The carbon flakes within the iron structure buffers this change of dimensions and assists in dimensional stability thus gaining resistance to distortion. The opposite can be seen in steel with no carbon where twisting and buckling can be observed.