Citizen Miyano BNJ-51SY
This model was not found in Citizen Machinery's current lineup when we checked on 2026-10-03 (lineup page). It may be a superseded or older model; the specifications below are as we last recorded them.
Image: cmj.citizen.co.jp, Citizen Machinery
Key Specifications
max bar capacity sp1
max bar capacity sp2
main spindle speed
main spindle power
sub spindle speed
sub spindle power
How much does the Citizen Miyano BNJ-51SY cost?
Estimated price range
Our best estimate for a mill-turn / multi-tasking machine in this class — not a quote from Citizen Machinery. Configuration moves it a long way.
Overview
The Citizen Miyano BNJ-51SY is a fixed-headstock lathe with two spindles and two turrets: a 12-station upper turret with a Y axis and an 8-station lower turret, both able to drive rotary tools at 6,000 rpm. The main spindle takes bar up to 51 mm (2.0 in) and runs to 5,000 rpm. The model is not in Citizen's current lineup, so a buyer is most likely looking at a used machine.
The two turrets are not equals. The upper one moves 168 mm in X1 and 250 mm in Z1, has ±40 mm of Y, and drives its tools with 2.2 kW. The lower turret's rotary tools have 0.75 kW, enough for drilling and tapping but not for real milling. Citizen rates both turrets for drilling to ø13 mm and tapping to M12×1.75 in S45C steel. The back spindle sits on its own slide with 88 mm of X2 and 650 mm of Z2, and the spindle end faces are 825 mm apart. Citizen counts 7 cutting axes in all.
The main spindle motor is 15/11 kW (15 min/cont.) and the back spindle motor 7.5/5.5 kW (15 min/cont.), both running to 5,000 rpm. For workholding the main spindle takes H-S22, DIN177E and Hainbuch 51 collets, the back spindle H-S22, H-S20 and DIN173E, and 6"/5" hollow power chucks are listed. The standard workpiece collection length is 120 mm.
On a used machine, check the Fanuc 0i-TF control, the condition of both spindles and which collet or chuck systems come with it. Plan for 5,550 kg, a 2,881 x 1,578 mm footprint and 1,775 mm of height.
Full Specifications
| Parameter | Value |
|---|---|
| Max Bar Capacity Sp1 | 51 mm (2.0 in) |
| Max Bar Capacity Sp2 | 42 mm (1.65 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 | 7.5/5.5 kW (10/7.5 hp) |
| Upper Turret Stations | 12 |
| Lower Turret Stations | 8 |
| Upper Turret Live Tool Speed | 6,000 RPM |
| Upper Turret Live Tool Power | 2.2 kW |
| Lower Turret Live Tool Speed | 6,000 RPM |
| Lower Turret Live Tool Power | 0.75 kW |
| Travel X1 | 168 mm (6.61 in) |
| Travel Z1 | 250 mm (9.84 in) |
| Travel X2 | 88 mm (3.46 in) |
| Travel Z2 | 650 mm (25.59 in) |
| Y Axis Travel | 80 mm (+/-40 mm) |
| Number of Axes | 7 cutting axes |
| Distance Between Spindles | 825 mm |
| Machine Weight | 5,550 kg |
| Floor Space | 2,881 x 1,578 mm |
| CNC Control | Fanuc 0i-TF |
| Items | BNJ-51SY7 |
| Sp2 | H-S22、H-S20、DIN173E |
| Tr2 | MAX M12×1.75(S45C) |
| Z1 Axis | 250mm |
| Y Axis | ±40mm |
| Z2 Axis | 650mm |
| Sp2 Cs | 7.5/5.5kw (15 min/cont.) |
| Machine Body Dimensions | 2,881×1,578mm |
| Distance Between Spindle End Faces | 825mm |
| Standard Workpiece Collection Length | 120 mm |
| Standard Machining Diametersp1 Sp2 | 51 mm |
| Max Spindle Speed Sp1 Sp2 | 5,000 min-1 |
| Collet Chuck Typesp1 | H-S22、DIN177E、Hainbuch 51 |
| Collet Chuck Typesp2 | H-S22、H-S20、DIN173E |
| Power Chuck Type Sp1 Sp2 | 6"/5"hollow chuck |
| Type of Tool Slidetr1 | 12st. |
| Type of Tool Slidetr2 | 8st. |
| Revolving Tool Capacitytr1 | Max.12 |
| Revolving Tool Capacitytr2 | Max.8 |
| Rotational Speed of Revolving Tools Tr1 Tr2 | 6,000min-1 |
| Max Drilling Diameter Tr1 Tr2 | MAX ø13mm |
| Max Tapping Diameter Tr1 Tr2 | MAX M12×1.75(S45C) |
| Turret Slide Stroke X1 Axis | 168mm |
| Turret Slide Stroke Z1 Axis | 250mm |
| Turret Slide Stroke Y Axis | ±40mm |
| Spindle Slide Stroke X2 Axis | 88mm |
| Spindle Slide Stroke Z2 Axis | 650mm |
| Motor for Spindle Sp1 Cs | 15/11kw (15 min/cont.) |
| Motor for Spindle Sp2 Cs | 7.5/5.5kw (15 min/cont.) |
| Machine Height | 1,775mm |
| Max Drilling Tr1 | 13 mm |
| Max Tapping Tr1 | M12 x 1.75 |
| Standard Collection Length | 120 mm |
Specifications compiled from manufacturer literature and industry references. Not independently verified against a published spec sheet — confirm with the manufacturer or an authorised dealer before making a purchasing decision.
Strengths & Limitations
Strengths
- Two turrets, 12 stations upper and 8 lower, with rotary tools on both at 6,000 rpm
- Upper turret has ±40 mm of Y travel for off-centre drilling and milling
- Back spindle slide with 650 mm of Z2 travel and 825 mm between the spindle end faces
- Both turrets drill to ø13 mm and tap to M12×1.75 in S45C
- Main spindle takes 51 mm (2.0 in) bar on a 15/11 kW (15 min/cont.) motor
Limitations
- Not in Citizen's current lineup, so check control, spindles and turrets on any used machine
- Lower-turret rotary tools are rated 0.75 kW, against 2.2 kW on the upper turret, so milling belongs on the upper turret
- Back spindle motor is 7.5/5.5 kW (15 min/cont.), half the main spindle rating
- Only the upper turret has a Y stroke in the table, so off-centre work is limited to one turret
Best For
Frequently Asked Questions
01
No, it is not in Citizen's current lineup. Machines on offer will be used, so confirm the Fanuc 0i-TF control, spindle condition and the tooling and workholding that come with it before buying.
02
The upper turret has 12 stations, ±40 mm of Y and 2.2 kW rotary tools. The lower turret has 8 stations and 0.75 kW rotary tools. Both run their rotary tools at 6,000 rpm and drill to ø13 mm and tap to M12×1.75 in S45C.
03
The back spindle slide strokes 88 mm in X2 and 650 mm in Z2, and the distance between the spindle end faces is 825 mm. The back spindle runs to 5,000 rpm on a 7.5/5.5 kW (15 min/cont.) motor.
04
The main spindle takes H-S22, DIN177E and Hainbuch 51 collet chucks; the back spindle takes H-S22, H-S20 and DIN173E. Citizen also lists 6"/5" hollow power chucks for the two spindles.
05
The machine weighs 5,550 kg, needs a 2,881 x 1,578 mm footprint and is 1,775 mm high. Add room for the bar feeder and for opening the guards when planning the layout.
Videos
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