ER32 Tapping Collet set. 20mm Shank with 16mm Square. 5mm Shank with 4mm Square. 6.3mm Shank with 5mm Square. 3.5mm Shank with 2.7mm Square. 4mm Shank with 3.15/3.2mm Square. 4.5mm Shank with 3.4mm Square.
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