CartridgesToolingTooling Boring Quill / Carbide Line Boring Bar This section introduces an overview of the series. Refer to the separate "SEC-Cartridge Unit / Micro Unit" catalog for details on Micro Units (holders, inserts, spare parts) and quill unit seat machining. Indexable Cartridges and Boring Quills G Carbide Line Boring Bar Carbide Line Bar Equipped with Cartridges G27