Corresponding to the inner hole of the spindle of the machine: 4.4mm or 4.9mm. Chucks size range 0.5mm,0.8mm ,1.0mm, 1.2mm ,1.5mm,1.8mm ,2.0mm ,2.4mm ,3.0mm ,3.2mm. Material: Brass. Size: the end of the sandwich is clamped directly: 4.3mm or 4.8mm.
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