Machine Tools Carbide Boring Bar Lathe12 Pcs Carbon Steel F1 Rough Boring Bar Mill Set for Milling CNC and Boring Machine Dia of Boring Head 75mm Product name F1 Boring Bar Dia. of Boring Head 18mm Model 12PCS for 18mm Dia.of Boring Heads F1-3" Boring Capacity 12-225mm Qty. of Boring Bar  12PCS