Technology for the World KURAKI

KURAKI’s unparalleled commitment to Horizontal Boring & Milling Machine Technology

KURAKI is always expanding its Horizontal Boring & Milling Machine lineup──optimal for machining large, heavy-duty workpieces──to meet the ever-changing requirements experienced by our customers. Our technologies ensure satisfaction in every aspect of our machines, exemplified by rigidity and high accuracy, thus producing repeated customer business.

Unsurpassed Structural Rigidity

In response to the recently increased size of diversified materials and workpieces, we have improved machine structures that meet higher cutting ability requirements. Full use of numerous technologies, such as a 150-mm / 6 inch spindle (a high-accuracy rotary table capable of loading up to 30 tons / 66000 lbs), along with others, enables deep hole drilling and multi-axis machining of large, heavy-duty workpieces. Under current diversifying machining conditions, KURAKI Horizontal Boring & Milling Machines fully support the expansion of new business.

Feeding-Type Spindle for Powerful Cutting

In addition to the movements of the X-, Y-, and Z-axes, feeding of the W-axis spindle achieves both accessibility to the workpiece and strong cutting ability. The feeding type spindle can easily perform heavy-duty deep hole drilling by means of a large-diameter spindle and large, high-rigidity bearings thus eliminating tool deflection or chattering due to longer tool lengths.
The maximum feeding length of the spindle is 350-900 mm. Ultraprecise assembly of the high-rigidity bearing supports powerful heavy-duty cutting.


Technology Spotlight
KURAKI Horizontal Boring &
Milling Machine’s convenient
“W-axis machining” technology

Spindle with large diameter / large mass/ long length

A dual structure in which a boring spindle moves into and out of a rotating milling spindle. Large-diameter bearings support its long span at three points.

KBT-13 series spindle

The bold, sturdy boring spindle and large-diameter bearings ensure high rigidity. Spindle structure of longer distance between bearings ensures longer and more accurate capacity.

Machining Center Spindle

Unsurpassed Torque 5 times to 8 times Greater than that of Machining Centers

The maximum torque of the KBT series is about 3000 to 4000 Nm, which is 5 to 8 times more than that of a normal machining center ―― powerful cutting ability exhibited in various hard-cutting materials such as complex materials containing titanium, manganese, or highly hardened materials.

KBT-13E Spindle Power-Torque Diagram

High-Accuracy Table Indexing for Wider Ranges of Machining

The rotary table capable of multiple face machining is accurately indexed at every 0.0001° by NC. Moreover, KURAKI original location pin (positioning pin) ensures accurate positioning at every 90°. In addition to the powerful hydraulic T-bolt clamp, the table sliding face has a back plate that restrains the table from floating to ensure stable rotations. The drive of double pinion gears achieves high-speed & high-accuracy indexing while performing continuous rotary milling.

High-Accuracy Positioning and High-Rigidity Bed and Column

Standard scale feedback systems in addition to NC perform high-accuracy positioning. The sturdy, large-diameter ball screw employed in each axis has a pretension mechanism that prevents expansion caused by load or heat. Each sliding face is heat-treated and ground and the mating face has a special synthetic resin excellent for long term wear. Our experienced engineers scrape the surface of the bed and then assemble the bed and column one by one with care, thus maintaining the machine’s high accuracy longevity.