Carmex External Multiple Threading Insert holder - For Carbide External/Internal Threading Inserts - SLE0020D21-3The Carmex External Multiple Threading Insert Holder is a precision tool accessory designed for CNC milling centers to perform external threading with multiple carbide inserts, delivering efficient, repeatable results. Multi insert capacity: Holds 34 carbide inserts per holder for extended cutting, reducing tool changes during threading operations. External threading focus: Specifically designed for external threading applications on CNC mills,