Machine Comparison
Okuma MULTUS B400II vs Okuma MULTUS B550
Okuma vs Okuma · Mill-Turn Machines
Summary
The Okuma MULTUS B400II and the Okuma MULTUS B550 are consecutive sizes in Okuma's mill-turn range, and the step up is in part size and turning power. The Okuma MULTUS B550 turns up to 830 mm (32.68 in) in diameter against 710 mm (27.95 in).
The larger machine also has the stronger spindle: 37/30 kW (50/40 hp) against 22/15 kW (30/20 hp). Its A2-11 spindle nose is standard, where the Okuma MULTUS B400II has a JIS A2-8 nose and lists JIS A2-11 as an option. Rapid traverse is shared at 40 m/min; the table gives it for X and Z on the Okuma MULTUS B400II and for three axes on the Okuma MULTUS B550.
Specifications Comparison
| Specification | Okuma MULTUS B400II | Okuma MULTUS B550 |
|---|---|---|
| Max Turning Diameter | 710 mm (27.95 in) | 830 mm (32.68 in) ▲ |
| Spindle Power | VAC 22/15 kW (VAC 30/20 hp) | 37/30 kW (50/40 hp) ▲ |
| Spindle Taper / Nose | JIS A2-8 [JIS A2-11] | A2-11 |
| Rapid Traverse | 40 m/min (X, Z) | 40/40/40 m/min (1,574/1,574/1,574 ipm) |
Advantages
Okuma MULTUS B400II
- JIS A2-8 spindle nose as standard, with JIS A2-11 as an option, for work set up around the smaller nose
- Covers chucking parts up to 710 mm (27.95 in) in turning diameter, enough where the work never reaches 830 mm (32.68 in)
Okuma MULTUS B550
- 830 mm (32.68 in) maximum turning diameter against 710 mm (27.95 in)
- 37/30 kW (50/40 hp) spindle against 22/15 kW (30/20 hp)
- A2-11 spindle nose as standard rather than as an option
Verdict
Choose by part diameter and by how heavy the cut is. Large chucking parts and heavy turning belong on the Okuma MULTUS B550, which offers 830 mm (32.68 in) of turning diameter, 37/30 kW (50/40 hp) and an A2-11 nose as standard. Shops whose work stays within 710 mm (27.95 in) and suits a JIS A2-8 nose are covered by the Okuma MULTUS B400II, which matches the larger machine's 40 m/min rapid traverse in X and Z.