Citizen Machinery CNC Lathes / Turning Centers

Citizen Miyano BNJ-51SY6

Est. $280,000 - $390,000 Specs verified 2026-10-03 · cmj.citizen.co.jp Updated 2026-10-03

Image: marucit.com, Citizen Machinery

Key Specifications

machining capacity standard turning length sp1 sp2

100 mm

machining capacity standard machining diameter sp1 sp2

51 mm dia./42 mm dia.

spindle spindle speed range sp1

50 - 5,000 rpm

spindle spindle speed range sp2

50 - 5,000 rpm

spindle type of collet chuck sp1

H-S22, DIN177E

spindle type of collet chuck sp2

JPN, H-S16, DIN171E

How much does the Citizen Miyano BNJ-51SY6 cost?

Estimated price range

Est.$280,000 - $390,000

Our best estimate for a cnc lathes / turning center in this class — not a quote from Citizen Machinery. Configuration moves it a long way.

Overview

The Citizen Miyano BNJ-51SY6 is a compact twin-spindle lathe that takes 51 mm dia. bar on its main spindle (SP1) and 42 mm dia. on its second spindle (SP2), with a 12st. upper turret (HD1), an 8st. lower turret (HD2) and ±40 mm of Y on HD1. Both spindles run 50 - 5,000 rpm, and the standard turning length is 100 mm.

Most of the cutting capacity sits on HD1. It can hold max. 12 revolving tools at 6,000 rpm, drill to 13 mm dia. and tap to M12×1.75, and it carries the Y axis. HD2 is a support turret: max. 4 revolving tools at 3,000 rpm, drilling to 10 mm dia. and tapping to M10×1.0. Revolving tools are listed in an OPT group of the table, so confirm which are included in a given quotation.

SP2 does not sit still. It is mounted on a spindle slide with 85 mm of X2 and 590 mm of Z2, long enough to reach across to SP1 for pick-off and then back-work against HD2. HD1 travels 165 mm in X1 and 246 mm in Z1. SP1 has a 15/11kw motor (15min./Cont.) and SP2 a 7.5/5.5kw motor (15min./Cont.), so the second spindle has enough power for real turning on the back end, not only finishing.

Collet chucks are H-S22 and DIN177E on SP1, and JPN, H-S16 and DIN171E on SP2; power chucks are 6"/5" hollow. Because SP2 tops out at 42 mm dia., parts made from full 51 mm bar need a reduced back end for the pick-off. The machine weighs 5,300 kg, stands 1,700 mm high and needs 2,840×1,560 mm of floor without the chip conveyor.

Full Specifications

Parameter	Value
Machining Capacity Standard Turning Length Sp1 Sp2	100 mm
Machining Capacity Standard Machining Diameter Sp1 Sp2	51 mm dia./42 mm dia.
Spindle Spindle Speed Range Sp1	50 - 5,000 rpm
Spindle Spindle Speed Range Sp2	50 - 5,000 rpm
Spindle Type of Collet Chuck Sp1	H-S22, DIN177E
Spindle Type of Collet Chuck Sp2	JPN, H-S16, DIN171E
Spindle Type of Power Chuck Sp1 Sp2	6"/5" Hollow
Turret Type of Turret Hd1	12st.
Turret Type of Turret Hd2	8st.
Revolving Tools Opt Maximum Number of Revolving Tools Hd1	max. 12
Revolving Tools Opt Maximum Number of Revolving Tools Hd2	max. 4
Revolving Tools Opt Spindle Speed Range Hd1	6,000 rpm
Revolving Tools Opt Spindle Speed Range Hd2	3,000 rpm
Revolving Tools Opt Maximum Drilling Diameter Hd1	13 mm dia.
Revolving Tools Opt Maximum Drilling Diameter Hd2	10 mm dia.
Revolving Tools Opt Maximum Tapping Diameter Hd1	M12×1.75
Revolving Tools Opt Maximum Tapping Diameter Hd2	M10×1.0
Slide Stroke Turret Slide Stroke X1 Axis	165 mm
Slide Stroke Turret Slide Stroke Z1 Axis	246 mm
Slide Stroke Turret Slide Stroke Y Axis	±40 mm
Slide Stroke Spindle Slide Stroke X2 Axis	85 mm
Slide Stroke Spindle Slide Stroke Z2 Axis	590 mm
Motors Spindle Motor Sp1 Cs	15/11kw(15min./Cont.)
Motors Spindle Motor Sp2 Cs	7.5/5.5kw(15min./Cont.)
Machine Dimensions Machine Height	1,700 mm
Machine Dimensions Floor Space	2,840×1,560 mm(Without Chip Conveyor)
Machine Dimensions Machine Weight	5,300 kg

Specifications sourced from cmj.citizen.co.jp — verified 2026-10-03

Strengths & Limitations

Strengths

51 mm dia. SP1 bar capacity in a machine of 5,300 kg
Y axis of ±40 mm on the 12-station HD1 turret
HD1 revolving tools at 6,000 rpm, drilling to 13 mm dia. and tapping to M12×1.75
SP2 on a spindle slide with 590 mm of Z2 travel
SP2 motor of 7.5/5.5kw (15min./Cont.) for genuine back-end turning

Limitations

SP2 takes 42 mm dia. at most, so 51 mm parts need a reduced back end
HD2 holds max. 4 revolving tools at 3,000 rpm
Revolving tools are listed as an option group in the table
Both spindles top out at 5,000 rpm

Best For

Bar parts up to 51 mm dia. with off-centre features Parts needing substantial turning on the back end Compact cells with limited floor space Drilling and tapping up to M12×1.75 from the upper turret

Frequently Asked Questions

01 Which turret has the Y axis on the BNJ-51SY6?

The Y axis of ±40 mm is on the turret slide of HD1, the 12-station upper turret, which also travels 165 mm in X1 and 246 mm in Z1. HD2 is the eight-station lower turret; SP2 moves on its own slide in X2 (85 mm) and Z2 (590 mm).

02 How many live tools can be fitted?

HD1 takes max. 12 revolving tools at 6,000 rpm and HD2 max. 4 at 3,000 rpm. The table lists revolving tools as an option (OPT), so check how many driven holders come with the machine.

03 What are the bar and collet capacities?

SP1 machines 51 mm dia. and SP2 42 mm dia. SP1 takes H-S22 and DIN177E collet chucks, SP2 JPN, H-S16 and DIN171E. Power chucks are 6"/5" hollow.

04 How does the BNJ-51SY6 compare with the BNE-51SY6?

The Miyano BNE-51SY6 has the same 51 mm dia. and 42 mm dia. spindle capacities but two 12-station turrets with 12+12 revolving tools, and weighs 7,800 kg. The BNJ-51SY6 is the lighter machine at 5,300 kg, with a smaller lower turret and a sliding SP2.