Okuma MULTUS B300II

Est. $350,000 - $550,000 Updated 2026-08-10

Key Specifications

Tool Capacity

20 tools

Rapid Traverse

40/26 m/min (1,575/1,024 ipm), X,Z/Y

standard chuck size

8 in

max machining diameter

630 mm (24.80 in)

max work length

900 mm (35.43 in)

spindle speed

45~5,000 min⁻¹ [38~3,800 min⁻¹ optional]

Overview

The Okuma MULTUS B300II is a horizontal multitasking machine combining a turning spindle with a milling spindle on a B-axis, sized a step above the compact end of the MULTUS B range. The standard chuck is 8 in, maximum machining diameter is 630 mm (24.80 in) and maximum work length is 900 mm (35.43 in).

That 900 mm length is the main practical difference from smaller machines in the family. It brings genuine shaft work into scope — pump shafts, spindles, drive components — alongside the chucked parts a multitasking machine is usually bought for, and it means a single machine can cover both without a second setup or a second machine.

The spindle runs 45~5,000 min⁻¹ standard with a 38~3,800 min⁻¹ option, on a JIS A2-6 nose or optionally A2-8. The VAC motor is rated 15/11 kW (20/15 hp) at the 20-minute and continuous ratings. The optional lower speed range paired with the larger A2-8 nose is the configuration to look at for heavier chucked work, since it trades top speed for the ability to carry a bigger chuck and pull harder at low rpm. For sustained cuts the 11 kW continuous figure is the honest planning number.

Rapids are 40 m/min (1,575 ipm) in X and Z and 26 m/min (1,024 ipm) in Y. The separate Y rapid confirms a real Y-axis, which combined with the B-axis milling head is what allows off-center holes, flats, pockets and angled features to be cut without moving the part.

Tool capacity is 20. On a machine intended to complete parts in one setup, that is the specification most likely to constrain a job: turning tools, boring bars, drills, taps and end mills for a single complex part can fill the magazine, leaving nothing loaded for the next job. Part families that share tooling are where this machine works best.

Machine dimensions are 4,035 × 2,257 × 2,587 mm, which is compact for the capability. A W specification adds a second spindle for back-end machining. The B300II suits aerospace, hydraulic and precision contract shops running medium-complexity turned and milled components.

Full Specifications

Parameter	Value
Standard Chuck Size	8 in
Max Machining Diameter	630 mm (24.80 in)
Max Work Length	900 mm (35.43 in)
Spindle Speed	45~5,000 min⁻¹ [38~3,800 min⁻¹ optional]
Spindle Nose	JIS A2-6 [JIS A2-8]
Spindle Motor	VAC 15/11 kW (20/15 hp), 20 min/cont
Rapid Traverse Rate	40/26 m/min (1,575/1,024 ipm), X,Z/Y
Tool Capacity	20 tools
Machine Dimensions	4,035 × 2,257 × 2,587 mm (158.86 × 88.86 × 101.85 in)
Spec Extension	W (second-spindle specification)

Specifications sourced from okuma.co.jp — verified 2026-08-09

Strengths & Limitations

Strengths

900 mm (35.43 in) of work length brings genuine shaft work — pump shafts, spindles, drive components — into scope alongside chucked parts
8 in standard chuck with 630 mm (24.80 in) maximum machining diameter covers both chucked and fixtured work
B-axis milling head plus a real Y axis, confirmed by its own 26 m/min (1,024 ipm) rapid, cuts off-center holes, flats, pockets and angled features without moving the part
Optional 38~3,800 min⁻¹ range paired with the larger JIS A2-8 nose trades top speed for a bigger chuck and harder pulling at low rpm
VAC spindle motor rated 15/11 kW (20/15 hp) at the 20-minute and continuous ratings
Compact for the capability at 4,035 × 2,257 × 2,587 mm, with a W specification available for a second spindle

Limitations

20 tool pockets is the specification most likely to constrain a job — turning tools, boring bars, drills, taps and end mills for one complex part can fill the magazine
11 kW continuous is the honest planning figure for sustained cuts, not the 15 kW 20-minute rating
The standard 5,000 min⁻¹ ceiling, or 3,800 min⁻¹ with the optional range, limits surface speed on small diameters
Y rapid of 26 m/min (1,024 ipm) lags the 40 m/min (1,575 ipm) available in X and Z
Choosing the optional lower speed range and A2-8 nose is a permanent trade that has to follow the dominant work

Best For

Aerospace, hydraulic and precision contract shops running medium-complexity turned and milled components Shaft work up to 900 mm (35.43 in) that also needs milled features Chucked parts on an 8 in chuck needing off-center holes, flats and pockets in one setup Part families that share tooling, so the 20-pocket magazine covers several jobs Shops replacing a lathe-plus-machining-center routing with a single machine

Frequently Asked Questions

01 What is the working capacity of the MULTUS B300II?

The standard chuck is 8 in, maximum machining diameter is 630 mm (24.80 in) and maximum work length is 900 mm (35.43 in). The machine itself measures 4,035 × 2,257 × 2,587 mm, which is compact for that capability.

02 Can the B300II handle shaft work?

Yes, and the 900 mm (35.43 in) work length is the main practical difference from smaller machines in the family. It brings pump shafts, spindles and drive components into scope alongside the chucked parts a multitasking machine is usually bought for, so one machine can cover both without a second setup.

03 Should I specify the optional spindle range and A2-8 nose?

The standard configuration is 45~5,000 min⁻¹ on a JIS A2-6 nose. The optional 38~3,800 min⁻¹ range with a JIS A2-8 nose is the one to look at for heavier chucked work, since it trades top speed for the ability to carry a bigger chuck and pull harder at low rpm. Choose against the dominant work, not the occasional job.

04 How much power does the B300II have for sustained cutting?

The VAC spindle motor is rated 15/11 kW (20/15 hp) at the 20-minute and continuous ratings. For cuts that run for a whole operation rather than a burst, 11 kW is the honest planning number and depth of cut should be sized against it.

05 Is the 20-tool magazine a limitation?

It can be. On a machine intended to complete parts in one setup, turning tools, boring bars, drills, taps and end mills for a single complex part can fill all 20 pockets, leaving nothing loaded for the next job. Part families that share tooling are where the machine works best.