High-Speed Steel, Charge 1: Crucible-Melted Tungsten-Chrome-Molybdenum Steel (Carnegie & Gladwyn 1918)

High-speed steel holds its edge when it is cutting hot. In Sheffield it was made like other crucible tool steel: the best Swedish bar iron melted in small clay pots in a coke fire, with tungsten, chromium and molybdenum added to the liquid iron. This is the first of three typical charges given by Carnegie and Gladwyn: 82 lb iron, 13 lb tungsten powder, 5 lb ferro-chrome and 4 lb ferro-molybdenum for 100 lb of steel. Source: D. Carnegie and S. C. Gladwyn, Liquid Steel (1918), pp. 74-77, 106-107 and 113. Unknown: how the Swedish iron, the tungsten powder and the ferro-molybdenum are made; the melting time; and how the ingot is worked into bar. The book stops at the liquid steel, so these are linked to unknown heads. Picture: the book's Fig. 29, crucible furnaces at Samuel Osborn & Co., Sheffield.