Machine Comparison
Okuma MULTUS B400II vs Okuma MULTUS B550
Okuma vs Okuma · Mill-Turn Machines
Summary
The Okuma MULTUS B400II and Okuma MULTUS B550 are both from Okuma's mill-turn machines lineup, making this a common upgrade or lineup decision for shops already invested in the Okuma ecosystem. The Okuma MULTUS B400II leads in rapid traverse (40 m/min (X, Z) vs 36 m/min (X), 30 m/min (Z)). The Okuma MULTUS B550 shows specification advantages in 7 categories, though the Okuma MULTUS B400II may still be the better choice depending on your shop's specific needs and the type of work you run. Both machines are proven performers in production environments and represent solid investments for shops in the market for a mill-turn machine.
Specifications Comparison
| Specification | Okuma MULTUS B400II | Okuma MULTUS B550 |
|---|---|---|
| Tool Capacity | 40 (options: 60, 80, 120) | 40 (options: 60, 80, 120, 160) |
| Rapid Traverse | 40 m/min (X, Z) ▲ | 36 m/min (X), 30 m/min (Z) |
| Bar Capacity | 80 mm (3.15 in) | 104 mm (4.09 in) ▲ |
| Max Turning Diameter | 710 mm (28.0 in) | 850 mm (33.5 in) ▲ |
| Control | Okuma OSP-P300SA | Okuma OSP-P300SA |
| Max Machining Length | 1,500 mm (59.1 in) | 3,000 mm (118.1 in) ▲ |
| Main Spindle Speed | 3,800 RPM ▲ | 3,000 RPM |
| Main Spindle Power | 30/22 kW (40/30 hp) | 37/30 kW (50/40 hp) ▲ |
| Main Spindle Torque | 500 Nm (369 ft-lb) | 700 Nm (516 ft-lb) ▲ |
| Spindle Nose | A2-8 | A2-11 |
| Milling Spindle Speed | 12,000 RPM ▲ | 10,000 RPM |
| Milling Spindle Power | 22/18.5 kW (30/25 hp) | 30/22 kW (40/30 hp) ▲ |
| Milling Tool Interface | Capto C6 | Capto C8 ▲ |
| B Axis Range | -30° to +195° (225° swing, 0.001° increment) | -30° to +195° (225° swing, 0.001° increment) |
| Price Range | $500,000 - $750,000 ▲ | $700,000 - $1,000,000 |
Advantages
Okuma MULTUS B400II
- Faster rapid traverse at 40 m/min (X, Z) reduces non-cutting time between operations
- Superior main spindle speed at 3,800 RPM vs 3,000 RPM
- Superior milling spindle speed at 12,000 RPM vs 10,000 RPM
- More competitive pricing at $500,000 - $750,000 compared to $700,000 - $1,000,000
Okuma MULTUS B550
- Superior bar capacity at 104 mm (4.09 in) vs 80 mm (3.15 in)
- Superior max turning diameter at 850 mm (33.5 in) vs 710 mm (28.0 in)
- Superior max machining length at 3,000 mm (118.1 in) vs 1,500 mm (59.1 in)
- Superior main spindle power at 37/30 kW (50/40 hp) vs 30/22 kW (40/30 hp)
- Superior main spindle torque at 700 Nm (516 ft-lb) vs 500 Nm (369 ft-lb)
Verdict
The Okuma MULTUS B550 edges ahead on specifications in this comparison, particularly in Bar Capacity and Max Turning Diameter. However, the Okuma MULTUS B400II remains competitive and may be the better choice depending on price, dealer support in your area, or specific workholding and tooling considerations. Both are capable machines — the best decision comes from running your actual parts and evaluating total cost of ownership including tooling, training, and service.