PLOUGH SHARES IN A NEW METAL

Press, Volume XCIII, Issue 27990, 9 June 1956, Page 7

PLOUGH SHARES IN A NEW METAL

Using a new metal—spheroidal graphite iron—a Devonshire firm are now manufacturing and exporting ploughshares which, it is claimed, have all the advantages of cast iron and steel ploughshares, but none of their disadvantages. In the past, cast iron ploughshares have been used mainly because of their cheapness, but also because of their fairly good wearing qualities. They have the disadvanvantage, however, of a high percentage of breakage when operating in stony ground. The alternative steel ploughshares have the advantage of resistance to breakage, but the disadvantage of higher c®st, lower durability, and a tendency for the beam of the plough to distort, resulting in bad alignment In spheroidal graphite iron, which has not previously been used for the manufacture of ploughshares, molecules ol carbon are found in globules, whereas in normal cast iron they are in strata formation. With cast iron, a blow is likely to cause the iron to break along the line of least resistance, that is, the carbon strata; but in spheroidal graphite there is no continuity line of weakness. The impact strength of the new ploughshares, it is said, is increased four or five times, and it wears better than cast iron because of a special cooling arrangement and oil treatment.