Citizen Miyano BNX-51MSY

$220,000 - $320,000 Updated 2025-03-15

Key Specifications

max bar capacity sp1

51 mm (2.0 in)

max bar capacity sp2

42 mm (1.65 in)

max machining length

100 mm (3.94 in)

main spindle speed

5,000 RPM

main spindle power

15/11 kW (20/15 hp)

sub spindle speed

5,000 RPM

Overview

The Citizen Miyano BNX-51MSY is a dual-spindle fixed-headstock CNC turning center with enhanced milling capability, Y-axis, and LFV chip-breaking technology for complete mill-turn production from 51 mm bar stock. The BNX platform represents Citizen's next-generation compact mill-turn design, combining two spindles, a live turret with Y-axis, and superimposition machining in a footprint that fits into shops upgrading from simpler turning centers.

The main spindle (SP1) reaches 5,000 RPM with 15/11 kW (20/15 hp) of power, while the sub-spindle (SP2) matches at 5,000 RPM with 11/7.5 kW (15/10 hp). The sub-spindle accepts 42 mm bar diameter and includes an independent X2 axis for overlap machining, enabling simultaneous front and back operations that significantly reduce cycle times. Both spindles use collet or power chuck workholding with 6-inch and 5-inch options respectively.

The 12-station turret accepts live tools at all positions, running up to 6,000 RPM with 4.0 kW (25 Nm) of rotary tool power — substantially more milling muscle than the BNA-42 series' 1.0 kW rotary motors. Y-axis travel of 80 mm (+/-40 mm) provides generous off-center machining range. Axis travels measure 168 mm on X1, 349 mm on Z1, 88 mm on X2, and 650 mm on Z2, with rapids of 24 m/min on X1 and Z1.

At 5,300 kg with a floor space of 2,630 x 1,540 mm, the BNX-51MSY is compact for its capability level. The Mitsubishi M830W control manages all axes including superimposition and simultaneous machining sequences. LFV (Low Frequency Vibration) chip-breaking software is available and particularly valuable at the 51 mm bar size where stainless steel and titanium generate substantial chip volumes that can wrap around tooling and cause problems during unattended operation.

The BNX-51MSY sits between the single-turret BND-51SY and the twin-turret BNE-51MSY in the Miyano lineup. It offers significantly more milling power than the BND while maintaining a simpler single-turret architecture that's easier to program and set up than the twin-turret BNE. The 4.0 kW/25 Nm rotary tool motor makes it capable of genuine milling operations rather than just light cross-drilling.

Typical applications include medical implant components, aerospace hydraulic fittings, automotive drivetrain parts, and industrial valve bodies where milling features represent a significant portion of total cycle time. The combination of strong milling capability, LFV chip control, and compact dual-spindle design makes the BNX-51MSY a compelling choice for shops that need real milling power without stepping up to a full multi-tasking machine.

Full Specifications

Parameter	Value
Max Bar Capacity Sp1	51 mm (2.0 in)
Max Bar Capacity Sp2	42 mm (1.65 in)
Max Machining Length	100 mm (3.94 in)
Main Spindle Speed	5,000 RPM
Main Spindle Power	15/11 kW (20/15 hp)
Sub Spindle Speed	5,000 RPM
Sub Spindle Power	11/7.5 kW (15/10 hp)
Turret Stations	12
Live Tool Stations	12
Live Tool Speed	6,000 RPM
Live Tool Power	4.0 kW (25 Nm)
Travel X1	168 mm (6.61 in)
Travel Z1	349 mm (13.74 in)
Travel X2	88 mm (3.46 in)
Travel Z2	650 mm (25.59 in)
Y Axis Travel	80 mm (+/-40 mm)
Rapid Traverse Xz	24 m/min (945 ipm)
Rapid Traverse Y	10 m/min (394 ipm)
Machine Weight	5,500
Floor Space	2,630 x 1,540 mm
Power Consumption	30 kVA
CNC Control	Mitsubishi M830W
Items	BNX-51MSY2
Standard Machining Diameter	SP1/SP2
Power Chuck Type	SP1/SP2
Distance Between Spindle End Faces	892 mm
Motor For Spindle	SP1 Cs
Sp2 Cs	1 / 7.5 kW (15 min / cont.)
Max Spindle Speed	SP1/SP2
Type Of Tool Slide	12st
Tool	□20 mm
Sleeve	φ25 mm
Slide Stroke	X1 axis
Z1 Axis	349 mm
Z2 Axis	650 mm
Y1 Axis	±40 mm
X2 Axis	88 mm
Revolving Tool Capacity	Max. 12
Machine Height	1,775mm
Sliding Headstock Type	A20
Bar Work	BNC42
Turning Machine	BNA42CY
High Precision Turning Machines	BNA42SY
Multi Station Machining Cell	MC20 III
Standard Machining Diametersp1 Sp2	ø65 mm/ø65 mm
Power Chuck Typesp1 Sp2	6” hollow chuck
Distance Between Spindle End Facessp1 Cs	18.5 / 15 kW (15 min / cont.)
Distance Between Spindle End Facessp2 Cs	1 / 7.5 kW (15 min / cont.)
Max Spindle Speedsp1 Sp2	5,000 min-1
Slide Strokex1 Axis	168 mm
Slide Strokez1 Axis	349 mm
Slide Strokez2 Axis	650 mm
Slide Strokey1 Axis	±40 mm
Slide Strokex2 Axis	88 mm
Inquiries	Feel free to get in touch with us by phone or online if you have any questions or need advice about any of our products or services.

Specifications sourced from cmj.citizen.co.jp — verified 2026-03-28

Strengths & Limitations

Strengths

4.0 kW (25 Nm) live tool motor delivers genuine milling capability at 6,000 RPM, far exceeding the 1.0-2.2 kW rotary motors on BNA and BND series machines
LFV chip-breaking technology eliminates stringy chip problems in stainless steel and titanium, enabling reliable unattended production at the 51 mm bar size
Independent X2 axis on the sub-spindle enables true overlap machining where both spindles work simultaneously during different phases of the cycle
650 mm Z2 sub-spindle travel provides exceptional clearance for part pickup and backworking, handling longer parts without interference concerns
Mitsubishi M830W control with superimposition capability delivers modern HMI with touch panel interface and advanced multi-axis synchronization
24 m/min rapids on X1 and Z1 keep non-cutting time low, improving productivity on high-volume production runs

Limitations

5,000 RPM maximum spindle speed is moderate; shops running small-diameter aluminum parts at high speed may want a machine with 6,000+ RPM capability
100 mm maximum machining length is relatively short compared to the BND-51SY's 320 mm, limiting the machine to compact parts only
Single turret shared between two spindles still limits simultaneous machining compared to twin-turret BNE and BNJ platforms
5,300 kg weight and 30 kVA power draw represent a significant step up in facility requirements from the compact BNA-42 series
Sub-spindle limited to 42 mm versus the main spindle's 51 mm, restricting full-diameter backworking on the largest parts

Best For

Medical device manufacturers producing complex implant components and surgical instruments from stainless steel and titanium bar stock requiring LFV chip control Aerospace hydraulic fitting production where cross-milling at 6,000 RPM with 25 Nm torque is needed alongside precision turning Automotive drivetrain component production needing strong milling capability from 51 mm bar without the complexity of a twin-turret machine Shops running unattended production in difficult materials where LFV chip-breaking technology prevents chip wrapping and tool breakage Contract manufacturers upgrading from BNA-42 or BND-51 platforms that need substantially more milling power for evolving part requirements Industrial valve and fitting manufacturers producing parts with deep cross-holes and milled features that demand real milling torque

Frequently Asked Questions

01 What does a new Citizen Miyano BNX-51MSY cost?

New BNX-51MSY machines typically range from $220,000 to $320,000 depending on tooling package, LFV option, high-pressure coolant, bar feeder, and parts catcher. The enhanced milling capability and LFV technology command a significant premium over the simpler BND-51SY. Used BNX-51MSY machines from 2016-2021 sell for $100,000-$200,000.

02 What is LFV chip-breaking technology?

LFV (Low Frequency Vibration) is Citizen's programmable chip-breaking technology that oscillates the cutting tool axis at controlled frequencies during turning operations. This intentionally breaks chips into short, manageable segments rather than producing long stringy chips that can wrap around the workpiece and tooling. LFV is particularly valuable for stainless steel, titanium, and other gummy materials during unattended production.

03 How does the BNX-51MSY compare to the BNE-51MSY?

The BNE-51MSY is a twin-turret machine with two 12-station turrets (24 total positions) and an additional X3/Z3 axis for independent sub-spindle machining. The BNX has a single turret with superimposition control. The BNE offers faster cycle times on complex parts through true simultaneous machining but costs $80,000-$120,000 more and requires more complex programming. Choose the BNX for simpler setups; choose the BNE for maximum simultaneous cutting.

04 What makes the 4.0 kW live tool motor significant?

The 4.0 kW (25 Nm) rotary tool motor is 2-4 times more powerful than the 1.0-2.2 kW motors on BNA and BND series machines. This means the BNX can handle genuine milling operations — deeper cuts, larger end mills, and harder materials — rather than being limited to light cross-drilling and tapping. It bridges the gap between a basic live-tooling lathe and a dedicated mill-turn multi-tasking machine.

05 Can the BNX-51MSY run both 51 mm and smaller bar stock?

Yes. The main spindle handles bar up to 51 mm with appropriate collets or chuck jaws. Smaller bar stock down to 20 mm runs with correctly sized collets. The sub-spindle accepts up to 42 mm. Most shops keep a set of collets covering their common bar diameters for quick changeover between part families.

06 What control features does the Mitsubishi M830W provide?

The M830W is Mitsubishi's current-generation CNC with a 15-inch color touch panel HMI, superimposition control for simultaneous two-spindle machining, C-axis interpolation, rigid tapping, and milling interpolation. It supports background editing, program storage, and tool life management for production environments. The touch panel interface is a significant usability improvement over older Mitsubishi controls.