If any axis of a machine tool not controlled by Items 1.B.2.a., 1.B.2.b., or 1.B.2.c. has a stated “positioning accuracy” of 6 μm or better (less) for grinding machines, and 8 μm or better (less) for milling and turning machines, both according to ISO 230/2 (1988), then the builder should be required to reaffirm the accuracy level once every eighteen months.
Hafnium correspondant aux descriptions suivantes: métal, alliages et composés de hafnium comprenant plus de 60 % de hafnium en poids, produits fabriqués dans ces matières, et déchets et chutes contenant du hafnium.