Jessop-Saville JO. Special is a basic hot work tool steel exhibiting good red-hardness and abrasion resistance at elevated temperatures. It is recommended for forging and extrusion dies. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on high temperature performance as well as heat treating, machining, and joining. Filing Code: TS-195. Producer or source: Jessop-Saville Ltd, Brightside Works.