Item Type: End Mill Tool Holder_x000D_ Optional Style: NT40-1-1/2-18 M16, NT30-1-1/2-18 M12_x000D_ NT40-1-1 / 2-18 M16: _x000D_ Material: High speed steel_x000D_ Connection Thread With Boring Head: 1-1 / 2-18UNF_x000D_ Applicable Machine: Boring machine_x000D_ Inner Hole: Approx. 16mm / 0.63in_x000D_ NT30-1-1 / 2-18 M12: _x000D_ Material: High speed steel_x000D_ Connection Thread With Boring Head: 1-1 / 2-18UNF_x000D_ Applicable Machine: Boring machine_x000D_ Inner Hole: Approx. 12mm / 0.47in 1Wide application, suitable for various machine tools 2Adopt hardened processing, high hardness and long service life 3Suitable for inner hole iron cutter head, hardened and durable 4Available in two styles for choice: NT40-1-1/2-18 M16, NT30-1-1/2-18 M12 5Made of high speed steel material, durable and long service lifePlease note that the new type and old type of this product will be sent randomly, and make sure you will not mind before ordering.1 xEnd Mill Tool Holder