Introducing Armour tooling’s HSS TiN countersink set. Theset includes 6 of the most popular sizes 6.3/8.3/10.4/12.4/16.5/20.5mm so theycan be used for a wide range of different tasks. Manufactured from high speedsteel (HSS) providing exceptional hardness suitable countersink for steel, Aluminium, cast iron, stainless steel, wood, plastics and many more materials.