Citizen Miyano BNC-51SYY
Key Specifications
Max Turn Length
max bar capacity
max chuck diameter
max turning diameter
main spindle speed
main spindle power
Overview
The Citizen Miyano BNC-51SYY is a twin-turret, twin-Y-axis, sub-spindle CNC turning center from Citizen's Miyano product line, handling bar stock up to 51mm (2 inches) and chuck work to approximately 100mm. The BNC-51SYY's full designation—51 (bar capacity) + S (sub-spindle) + Y (Y-axis upper turret) + Y (Y-axis lower turret)—communicates the machine's complete multi-tasking architecture: dual independent Y-axis turrets and a full sub-spindle for complete part machining in a single clamping. This makes the BNC-51SYY one of the most capable machines in the Miyano line for complex turned and milled parts in a bar-fed production environment.
The twin-Y-axis configuration is the BNC-51SYY's defining feature. Both upper and lower turrets carry independent Y-axis travel, enabling simultaneous off-center milling on both sides of the part or coordinated dual-turret operation for maximum throughput. Cross-drilled holes, keyways, hex profiles, radial milled pockets, and other non-turned features are produced entirely within the main turning cycle without any workpiece transfer. When combined with the sub-spindle, the BNC-51SYY achieves true complete-part machining—front turning and milling, cutoff, back-work with milling on the sub-spindle—all within a single automated cycle.
With 51mm bar capacity, the BNC-51SYY covers a wide range of production parts: hydraulic valve bodies, pneumatic actuator components, automotive connector housings, medical housing components, and precision industrial fittings that require turned OD and ID features combined with milled and drilled secondary features. The 51mm bar range overlaps the upper end of Swiss-type lathe capability and extends into chuck-work territory, giving the BNC-51SYY flexibility across a broader part family than a single-purpose machine.
The BNC-51SYY uses a FANUC CNC control, consistent with the Miyano line's positioning for production shops where FANUC programming knowledge is standard. Turret indexing times, rapid traverse rates, and the machine's slant-bed, chip-conveyor design are all optimized for high-volume production rather than prototype or low-volume work. The machine supports bar feeding for fully automated production and is routinely paired with Citizen/Miyano-compatible bar feeders for lights-out operation.
Full Specifications
| Parameter | Value |
|---|---|
| Max Bar Capacity | 51 mm (2.008 in) |
| Max Chuck Diameter | Approx. 100 mm (3.94 in) |
| Max Turning Diameter | 100 mm (3.94 in) |
| Max Turning Length | 200 mm (7.87 in) |
| Main Spindle Speed | 5,000 RPM |
| Main Spindle Power | 11 / 15 kW (15 / 20 HP) |
| Sub Spindle Speed | 5,000 RPM |
| Sub Spindle Power | 5.5 / 7.5 kW (7.4 / 10 HP) |
| Upper Turret Tools | 12 stations |
| Lower Turret Tools | 12 stations |
| Y Axis Upper Travel | +/- 40 mm |
| Y Axis Lower Travel | +/- 40 mm |
| Driven Tool Speed | 5,000 RPM |
| CNC Control | FANUC |
| Machine Weight | Approx. 6,500 kg (14,330 lbs) |
| Cnc | CNC自動旋盤がどんな機能や特徴を持っているか解説。 |
| Creation | 当社の情報誌「CREATION」のバックナンバーを掲載。 |
Specifications sourced from cmj.citizen.co.jp — verified 2026-03-28
Strengths & Limitations
Strengths
- [object Object]
- [object Object]
- [object Object]
- [object Object]
Limitations
- [object Object]
- [object Object]
- [object Object]
Best For
Frequently Asked Questions
01
The designation breaks down as: BNC (Miyano's base turning center series) + 51 (51mm bar capacity) + S (sub-spindle) + Y (Y-axis on upper turret) + Y (Y-axis on lower turret). Each letter indicates a key machine capability. The SYY suffix represents the most capable configuration in the BNC-51 family, with complete multi-tasking capability on both spindles and both turrets.
02
The BNC-51SYY is a conventional turret-based turning center with twin Y-axis turrets and sub-spindle, handling up to 51mm bar. The ABX-38 uses a sliding headstock design for 38mm bar production, more similar to Swiss-type architecture. The BNC-51SYY offers more milling capability through its twin-Y dual-turret design; the ABX-38 is optimized for sliding-headstock production turning in the 38mm range. They suit different part profiles and production philosophies.
03
New BNC-51SYY pricing in the full SYY configuration typically ranges from $250,000 to $380,000. The twin Y-axis, sub-spindle configuration is the most capable and highest-priced variant in the BNC-51 range. Simpler BNC-51 configurations without dual Y-axis carry lower price points.
04
Yes. The BNC-51SYY supports simultaneous dual-turret operation, enabling the upper and lower turrets to cut concurrently on the main spindle or coordinated front/back-work with the sub-spindle active. Properly programmed simultaneous dual-turret operation is the key driver of cycle time reduction on complex parts.
05
The BNC-51SYY's FANUC control is supported by virtually every major CAM package including Mastercam, ESPRIT, Siemens NX, and others. Multi-turret, multi-spindle post processors for FANUC-controlled turning centers are widely available. Manual programming of simultaneous dual-turret operation is also common in experienced production shops.
Community Discussions
Community discussion — I took your advice and bought a Mitutoyo : r/Machinists - Reddit
Community discussion — Fake Mitutoyos? Please help! : r/Machinists - Reddit
Options and configuration advice — benchtop lathe/mill recommendations? : r/Machinists - Reddit
Community discussion — Best and worst CNC machines and brands you've ever used ...
Links to community discussions. Summaries are editorial — visit the original thread for full context.
