Intermediate sleeve for MK shank • ISO 7388-1 (DIN 69871), form AD • Made of alloyed tool steel • Hardened to 58 ± 2 HRC, minimum 0.5 mm deep • Tensile strength in the core after case hardening approximately 950 N/mm² • Taper DIN 254 • Taper angle tolerance AT3 • Runout accuracy 0.01 mm • Surface accuracy of the taper Ra < 1 μm • Balance quality G 6.3 at 15000 min⁻¹.