Kuraki KM-6VA

$350,000 - $650,000 Updated 2026-03-17

Key Specifications

X Travel

2,000 mm (78.7 in)

Y Travel

1,000 mm (39.4 in)

Z Travel

800 mm (31.5 in)

Max Spindle

8,000 RPM (12,000 RPM optional)

Spindle Taper

HSK-A63 (HSK-A100 optional)

Tool Capacity

40 (expandable to 80)

Overview

The Kuraki KM-6VA is a large-bed vertical machining center designed for high-precision milling, drilling, boring, and tapping of large prismatic workpieces in a vertical spindle configuration. The KM series represents Kuraki's extension of its precision machining philosophy — developed over decades of floor-type boring mill manufacturing — into the vertical machining center format, bringing the same rigidity, thermal stability focus, and accuracy standards to a vertical configuration suited for large, flat, and low-profile workpieces that are difficult to orient on a horizontal machine.

The '6VA' designation reflects the machine's 6-series table size (nominally 2,000 mm or larger in the longest dimension) and the vertical spindle ('V') with automatic configuration. The KM-6VA uses a fixed-table, moving-gantry or moving-column design that allows the spindle to traverse the full table length and width, covering the entire workpiece surface without repositioning. The large table handles workpieces typical of mold and die manufacturing, aerospace tooling, automotive stamping die plates, and large industrial machine bed machining.

Kuraki designs the KM-6VA with a focus on flatness and parallelism accuracy across the full table travel — a differentiating requirement for large-bed VMCs compared to smaller machines where axis straightness errors are less consequential. The machine bed and column are cast from high-grade Meehanite-type cast iron, with ribbing designed by finite element analysis to maximize static and dynamic stiffness. The column and spindle carriage use precision linear guideways on X, Y, and Z axes with preloaded ball carriages for minimal axis play and high dynamic stiffness during interrupted cuts and face milling operations on large workpieces.

The KM-6VA spindle is an HSK-A63 or HSK-A100 design (depending on configuration) with speeds up to 8,000 RPM on the standard spindle, suitable for carbide tooling in steel, cast iron, and aluminum. An optional high-speed spindle configuration extends speeds to 12,000 or 15,000 RPM for aluminum tooling and die cavity work. Through-spindle coolant at up to 70 bar supports drilling and milling in deep pockets and cross-bores. The automatic tool changer holds 40 tools standard, expandable to 80 or more for complex multi-operation workpieces.

The KM-6VA competes in the large-bed VMC segment with machines from Okuma (MCV-A series), Makino (V Series large-bed), Mazak (VTC series), and domestic US builders like Haas (VF-12/14/18 series). Kuraki's differentiation in this segment is its boring mill heritage — the KM-6VA offers tighter positional accuracy and flatness specifications than most general-purpose large-bed VMCs, positioning it for precision mold, die, and aerospace tooling work rather than the general-purpose large-part machining market. For shops that need a large-bed VMC with boring mill accuracy, the KM-6VA is a strong Japanese alternative.

Full Specifications

Parameter	Value
Table Size	2,000 x 1,000 mm (78.7 x 39.4 in)
X-Axis Travel	2,000 mm (78.7 in)
Y-Axis Travel	1,000 mm (39.4 in)
Z-Axis Travel	800 mm (31.5 in)
Max Spindle Speed	8,000 RPM (12,000 RPM optional)
Spindle Taper	HSK-A63 (HSK-A100 optional)
Spindle Motor Power	30 kW (40.2 hp)
Spindle Torque	350 Nm
Max Workpiece Weight	5,000 kg (11,023 lb)
Rapid Traverse Rate	24 m/min (945 ipm) — X/Y; 20 m/min (787 ipm) — Z
Tool Capacity	40 (expandable to 80)
Positioning Accuracy	0.007 mm / full stroke (7 µm)
Flatness Accuracy	0.02 mm / full table (20 µm)
CNC Control	Fanuc 31i-B5
Machine Weight	22,000 kg (48,502 lb)

Specifications sourced from us.dmgmori.com — verified 2026-03-28

Strengths & Limitations

Strengths

Boring mill heritage accuracy standards applied to a large-bed VMC format deliver 7 µm positioning accuracy and 20 µm flatness over full table travel — tighter than most general-purpose large-bed VMCs in this class
2,000 x 1,000 mm table with 5,000 kg load capacity handles large die plates, aerospace tooling, and industrial machine components that 1,000 mm class VMCs cannot accommodate
Fixed-table moving-gantry design eliminates workpiece weight effects on axis accuracy — heavy workpieces do not deflect the table or affect axis straightness, a critical advantage for precision die and tooling machining
Fanuc 31i-B5 control with AICC (AI Contour Control) and high-speed interpolation supports smooth complex surface machining for mold and die cavity work
Kuraki's established North American service network supports the KM-6VA with the same infrastructure used for the KBM boring mill line — spare parts and service technicians are available without the delays common with smaller Japanese VMC importers

Limitations

8,000 RPM standard spindle speed is adequate for steel and cast iron but slower than competitors optimized for aluminum die cavity work at 15,000+ RPM; high-speed spindle option increases cost
At 40 tools standard, the base tool magazine is modest for complex multi-operation large-part work; the 80-tool expansion option is nearly essential for most serious applications and adds to the base price
The KM-6VA's price of $350K–$650K is at the premium end of the large-bed VMC segment; general-purpose large-part shops can find comparable table sizes from Haas or similar builders at significantly lower cost if precision is not the primary requirement

Best For

Mold and die manufacturers producing large automotive stamping dies, plastic injection molds, and forging dies requiring high flatness accuracy and precision bore positioning across large table surfaces Aerospace tooling manufacturers machining large jigs, fixtures, and assembly tooling where positional accuracy across the full table length must be maintained to sub-10-micron levels General engineering job shops with a specialty in large flat workpieces: machine bases, sliding table surfaces, large hydraulic manifold plates, and industrial equipment frames requiring precise surface milling and boring Automotive die shops requiring a large-bed VMC that can perform the precision cavity milling for complex progressive stamping dies while maintaining flatness accuracy across the full die plate

Frequently Asked Questions

01 How does the KM-6VA differ from Kuraki's KBM horizontal boring mill line?

The KBM series is a floor-type horizontal boring mill designed primarily for large rotational and prismatic workpieces that require boring large-diameter holes at depth — turbine casings, engine blocks, large housings. The KM-6VA is a vertical machining center designed for large flat prismatic workpieces — die plates, tooling bases, large machine components — where the vertical spindle provides better access to the workpiece top surface and the fixed-table design handles heavy flat parts efficiently.

02 What is the maximum bore size the KM-6VA can produce?

The KM-6VA can bore holes through circular interpolation from the minimum tooling diameter up to approximately 300–400 mm diameter using large-diameter boring heads or interpolated milling. For larger diameter bores, the machine can use single-point boring bars in the spindle with the table stationary. The maximum practical precision bore diameter depends on available tooling and the specific bore depth and tolerance requirements.

03 Is the KM-6VA suitable for 5-axis machining?

The standard KM-6VA is a 3-axis machine (X, Y, Z). Five-axis capability requires the addition of a tilting rotary table (trunnion table) or an optional 2-axis swiveling spindle head. Kuraki offers these options for specific applications requiring five-axis capability on large workpieces. For dedicated five-axis large-part work, however, a machine designed from the ground up for 5-axis capability may be a better match.

04 How does the fixed-table design affect accuracy compared to moving-table VMCs?

In fixed-table designs, the heavy workpiece remains stationary while the spindle head moves — this means the workpiece weight does not change the geometry of the axis slides as the table moves. In moving-table VMCs, a heavy workpiece moving in X and Y creates variable loads on the table guideways, which can cause small but measurable changes in axis straightness. The fixed-table KM-6VA maintains consistent accuracy regardless of workpiece weight distribution, which is why it is preferred for precision large-part work.

05 What coolant systems are available on the KM-6VA?

The KM-6VA supports flood coolant as standard, with through-spindle coolant (TSC) at 30 bar standard and 70 bar as an option. TSC at 70 bar is strongly recommended for deep drilling (L/D > 5), deep pocket milling in cast iron, and any application with difficult chip evacuation. An automatic chip conveyor handles large volumes of chips from cast iron and aluminum machining, which is important given the large table area and typical long cycle times on large die and tooling workpieces.