Okuma MULTUS B400II-W

USD 600,000 - USD 850,000 Updated 2026-03-16

Key Specifications

Spindle Taper

HSK 63

Tool Capacity

40 standard (options: 60, 80, 120)

Rapid Traverse

40 m/min (1,575 ipm) on X and Z

max turning diameter

710 mm (28.0 in)

max machining length

1,500 mm (59.1 in)

main spindle speed

3,800 RPM

Overview

The Okuma MULTUS B400II-W is the twin-spindle done-in-one variant of the B400II, featuring a standard integrated sub-spindle (W-axis) that transforms the machine into a complete parts-out platform. The B400II-W ships with the sub-spindle as a standard production specification along with the full B-axis milling spindle, purpose-built for complete part machining without secondary operations.

The main turning spindle delivers 30/22 kW (40/30 hp) at up to 3,800 RPM with 500 Nm (369 ft-lb) of torque through an A2-8 nose supporting 80 mm (3.15 in) bar stock. The integrated sub-spindle runs up to 3,500 RPM with 22/15 kW (30/20 hp) and 300 Nm (221 ft-lb), positioned on the W-axis which travels up to 800 mm (31.5 in) to pick parts directly from the main spindle automatically for back-turning, cross-drilling, and angular work without the operator touching the part.

The B-axis milling spindle swings 225 degrees on a direct-drive motor with 0.001-degree indexing. At 12,000 RPM and 22/18.5 kW through a Capto C6 interface, it cuts aluminum, steel, and titanium at full machining center speeds. Y-axis travel of 200 mm (7.9 in) provides generous off-center reach on both spindle sides.

Linear travels are 480 mm on X and 1,500 mm on Z. Rapid traverse is 40 m/min (1,575 ipm). The standard ATC holds 40 tools with options for 60, 80, or 120. An optional lower turret adds a simultaneous second cutting point. Okuma Thermo-Friendly Concept protects part-handoff accuracy across shifts. The Collision Avoidance System covers both spindle zones in 3D simulation.

Direct competitors include the Mazak Integrex i-400S, DMG Mori CTX beta 2000 TC, and Nakamura-Tome MX-250. New pricing runs from USD 600,000 to USD 850,000 fully configured. Machine weight is approximately 20,000 kg (44,092 lb). Specs based on Okuma published product data.

Full Specifications

Parameter	Value
Max Turning Diameter	710 mm (28.0 in)
Max Machining Length	1,500 mm (59.1 in)
Main Spindle Speed	3,800 RPM
Main Spindle Power	30/22 kW (40/30 hp)
Main Spindle Torque	500 Nm (369 ft-lb)
Main Spindle Nose	A2-8
Bar Capacity	80 mm (3.15 in)
Sub Spindle Speed	3,500 RPM (standard, W-axis)
Sub Spindle Power	22/15 kW (30/20 hp)
Sub Spindle Torque	300 Nm (221 ft-lb)
W Axis Travel	800 mm (31.5 in)
Milling Spindle Speed	12,000 RPM
Milling Spindle Power	22/18.5 kW (30/25 hp)
Milling Tool Interface	Capto C6
B Axis Range	-30 to +195 degrees (225 degree swing, 0.001 degree increment)
X Axis Travel	480 mm (18.9 in)
Y Axis Travel	200 mm (7.9 in)
Z Axis Travel	1,500 mm (59.1 in)
Tool Capacity	40 standard (options: 60, 80, 120)
Rapid Traverse Rate	40 m/min (1,575 ipm) on X and Z
Chuck Size	10 in main / 8 in sub
Lower Turret	Optional
Machine Weight	approximately 20,000 kg (44,092 lb)
CNC Control	Okuma OSP-P300L
Manufacturer	DMG Mori
Model	DMC 125
Spindle Taper	HSK 63
Spindle Bore	150.11 mm

Specifications sourced from machinio.com — verified 2026-03-28

Strengths & Limitations

Strengths

Standard integrated sub-spindle on the W-axis enables complete done-in-one production directly off bar stock, eliminating second-op setups and positional error accumulation between operations
200 mm Y-axis travel covers off-center milling, cross-drilling, and complex features on both spindle sides, a genuine advantage over machines with narrower Y-axis ranges
B-axis milling spindle with 225-degree swing and 12,000 RPM Capto C6 interface delivers true machining center cutting performance, not just driven turret live tools
Collision Avoidance System (CAS) simulates both spindle zones simultaneously, protecting the machine during complex twin-spindle cycles
Thermo-Friendly Concept maintains sub-spindle alignment across production shifts, protecting automatic part-handoff accuracy that the done-in-one cycle depends on
Optional lower turret enables simultaneous cutting: roughing on the lower turret while the milling spindle finishes, reducing cycle time on long-running parts
500 Nm main spindle torque handles aggressive roughing on large-diameter steel and alloy stock before the milling spindle takes over for finishing

Limitations

Capital cost demands consistent high-complexity part volume to justify versus buying a separate lathe and machining center
Approximately 20,000 kg machine weight requires substantial floor preparation and specialist rigging before delivery
3,800 RPM main and 3,500 RPM sub-spindle speeds are too slow for productive high-speed aluminum turning; a B200II or B250II is better for aluminum-primary shops
Programming twin-spindle simultaneous cycles with CAS is significantly more complex than single-spindle multitasking; plan for steep learning curve and dedicated CAM post configuration
40-tool standard magazine is inadequate for most complex done-in-one programs; budget for the 80 or 120-tool expansion from the start
OSP control for twin-spindle multitasking differs substantially from Fanuc and MAZATROL, requiring committed operator and programmer retraining

Best For

Bar-fed production of complex medium-to-large steel and alloy parts where automated main-to-sub-spindle handoff produces complete parts without human intervention Aerospace manufacturers machining actuator housings, valve bodies, and fittings requiring turning and milling on both ends in single-datum concentricity Oil and gas shops producing long valve stems, spool bodies, and drill string components with complex geometry on both ends in a single cycle Precision job shops running high-mix, medium-volume work where eliminating second-op setups cuts lead time and reduces positional errors Defense and precision industries machining connectors, housings, and hydraulic manifolds where roundtrip part accuracy requires continuous chucking Shops already running a MULTUS B400II looking to add a dedicated high-volume twin-spindle cell alongside it

Frequently Asked Questions

01 What is the difference between the MULTUS B400II and the B400II-W?

The B400II-W includes an integrated sub-spindle on the W-axis as a standard production specification. The base B400II treats the sub-spindle as an add-on option. The -W designation also signals a 10-inch main chuck and 8-inch sub-chuck as standard. If complete done-in-one machining is your primary goal, the B400II-W is the right starting point rather than retrofitting the option later.

02 What does the W-axis do?

The W-axis drives the sub-spindle along the machine Z-axis corridor. It moves the sub-spindle into position to pick a partially machined part from the main spindle automatically, then repositions for sub-spindle machining. W-axis travel on the B400II-W is 800 mm (31.5 in), providing enough reach for the part handoff across the 1,500 mm Z-axis work zone.

03 Can the main spindle and sub-spindle run simultaneously?

Yes, with the optional lower turret installed. The lower turret adds a simultaneous second cutting point that can rough on the sub-spindle side while the B-axis milling head finishes on the main spindle side. Without the lower turret, the machine alternates between spindles, which is still productive but not true simultaneous twin-spindle cutting.

04 How does the B400II-W compare to the Mazak Integrex i-400S?

Both are twin-spindle 400-class multitasking machines. The Mazak i-400S uses MAZATROL SmoothAi conversational programming. The Okuma B400II-W has Thermo-Friendly Concept for better thermal stability and Collision Avoidance System covering both spindle zones. The choice typically comes down to control preference (OSP vs MAZATROL) and regional dealer support quality.

05 What tool magazine size should I specify?

Specify the 80-tool or 120-tool magazine. A done-in-one cycle on a complex part can easily consume 30-50 tools for main spindle work plus another 20-30 for the sub-spindle side plus backup tools. The 40-tool standard is inadequate for serious production work on the B400II-W.

06 Is the B400II-W suitable for titanium machining?

Yes. The 500 Nm main spindle torque and 300 Nm sub-spindle torque provide cutting force for titanium, and the B-axis milling spindle at 12,000 RPM with 22 kW handles titanium milling within appropriate surface speed limits. High-pressure coolant should be specified from the factory. Capto C6 suits the rigid tooling setups that titanium machining requires.