English size is 1/2” across flutes.  5/8” is dia. of steel.

Pro-PM turning tools are the 'elite' of all turning chisels. Made from an advanced Particle Metal, the molten steel has been compressed and sintered giving our Pro-PM turning tools a cutting edge which lasts up to four/five times that of a conventional High Speed Steel tool. The chisels are hardened to between 66° and 68° Rockwell, enabling the tools to have a vastly superior wear resistance, excellent grindability, superior toughness, a high working hardness and a high retention of hardness. The ergonomically designed beech handles fitted to these tools make the finished chisels unbeatable.