Yamazaki Mazak CNC Lathes / Turning Centers

Mazak Quick Turn Nexus 550-II

$420,000 – $620,000 Updated 2026-03-17

Key Specifications

Max Spindle

1,500 RPM

Tool Capacity

12-position VDI 80 turret

Spindle Power

45 kW (60 hp) at 25% ED; 30 kW (40 hp) continuous

Max Turn Length

1,800 mm (70.87 in)

max turning diameter

830 mm (32.68 in)

swing over bed

46.33"

Overview

The Mazak Quick Turn Nexus 550-II is one of the largest CNC turning centers in the NEXUS product family, positioned for shops that routinely turn workpieces in the 600–900 mm diameter range. With a 24-inch chuck, 830 mm maximum turning diameter, and 45 kW (60 hp) built-in spindle motor, the QTN-550-II is built for heavy industry segments including oil and gas, power generation, offshore, and large aerospace components.

The 45-degree slant bed casting provides excellent chip evacuation and operator access on large workpieces. The thermally symmetric headstock is matched to the machine's larger mass, and the full NEXUS-II generation updates carry over — improved bearing preload, enhanced coolant-through capability, and MAZATROL SmoothG control with updated thermal compensation algorithms. Maximum turning length on the standard bed is 1,800 mm (70.9 in). The A2-15 spindle nose accepts large-bore workholding up to 24-inch chucks.

Spindle speed tops out at 1,500 RPM — characteristic of a machine designed for large-diameter roughing rather than small-feature finishing. The 12-position turret with VDI 80 tooling provides the rigidity needed for high-chip-load cutting in alloy steel and stainless. High-pressure coolant through the turret is standard on the -II generation, feeding coolant directly to the cutting edge on deep bores and heavy roughing.

The QTN-550-II competes against the Okuma LB6000 EX II, Doosan Puma 700, and Hankook heavy lathes. In this class, Mazak differentiates with MAZATROL SmoothG's ease of use and the factory support network. For shops stepping up from a 450-class machine to handle truly large parts, the 550-II is the logical Mazak platform.

Full Specifications

Parameter	Value
Max Turning Diameter	830 mm (32.68 in)
Max Turning Length	1,800 mm (70.87 in)
Swing Over Bed	46.33"
Max Spindle Speed	1,500 RPM
Spindle Motor Power	45 kW (60 hp) at 25% ED; 30 kW (40 hp) continuous
Spindle Torque	4,800 Nm (3,540 ft-lb) at 25% ED
Spindle Nose	A2-15
Chuck Size	610 mm (24 in)
Bar Capacity	12.5"
Tool Capacity	12-position VDI 80 turret
X Axis Travel	475 mm (18.7 in)
Z Axis Travel	1,855 mm (73.0 in)
Rapid Traverse X	20 m/min (787 ipm)
Rapid Traverse Z	25 m/min (984 ipm)
Machine Weight	22,000 kg (48,502 lb)
CNC Control	MAZATROL SmoothG CNC
Model	QUICK TURN NEXUS 550 MY IIDiscontinued Model
Brand	MAZAK
Type	CNC Lathes
Bar Capacity125power80 Hpmax Rpm750 Rpm	Turning Dia31.8"Swing46.33"ControlCNC (Mazatrol Matrix Nexus 2)
Power	80 hp
Max Rpm	750 RPM
Turning Dia	31.8"
Cnc Control	CNC (Mazatrol Matrix Nexus 2)

Specifications sourced from machinetools.com — verified 2026-03-28

Strengths & Limitations

Strengths

4,800 Nm of spindle torque enables extremely aggressive roughing cuts on large-diameter alloy steel, stainless, and Inconel workpieces
24-inch chuck and 830 mm turning diameter handle workpiece sizes that most job shops need to send to specialty heavy turning shops
VDI 80 turret provides exceptional rigidity and tool-clamping force appropriate to the scale of cuts being taken
Standard high-pressure coolant through the turret on the -II generation improves chip breaking and tool life on deep bores in tough materials
MAZATROL SmoothG conversational programming allows operators to set up complex large-part turning programs without CAM software
45-degree slant bed with large-opening guarding provides excellent chip management and operator ergonomics when loading heavy workpieces

Limitations

1,500 RPM maximum spindle speed is too slow for smaller-diameter finishing passes — the machine is optimized for large-diameter work only
At 22,000 kg, the QTN-550-II requires significant floor reinforcement and careful crane access planning for installation
Capital cost exceeding $420,000 new limits this machine to shops with consistent demand for large-diameter turning
No live tooling or Y-axis option — all secondary operations must be performed on separate equipment
Long delivery lead times common in this class; shops should plan 6–12 months from order to installation

Best For

Oil and gas manufacturers producing large-diameter wellhead components, blowout preventer bodies, and valve housings Power generation shops turning large turbine shafts, generator housings, and heat exchanger flanges Offshore and marine manufacturers producing large propulsion shafts, thruster components, and deck equipment parts Mining and heavy equipment manufacturers turning large-diameter gears, bushings, and shaft assemblies Defense contractors producing large artillery, naval, and armored vehicle components requiring heavy-duty turning capacity

Frequently Asked Questions

01 What does a Mazak Quick Turn Nexus 550-II cost?

New pricing ranges from approximately $420,000 to $620,000 depending on bed length, tooling setup, and optional packages. High-pressure coolant and chip conveyor are standard on most configurations. Used machines are relatively rare; when they appear on the secondary market they typically sell in the $180,000–$320,000 range.

02 How does the QTN-550-II differ from the QTN-450-II?

The 550-II steps up to a 24-inch chuck vs 21-inch, 830 mm turning diameter vs 600 mm, A2-15 spindle nose vs A2-11, and 4,800 Nm torque vs 2,450 Nm. Machine weight increases to 22,000 kg from 12,500 kg. The 550-II is the appropriate choice when parts regularly exceed 550 mm in diameter.

03 Can the QTN-550-II turn long shafts?

Yes. With 1,800 mm turning length and tailstock support, the 550-II handles long-shaft work. A steady rest is available for supporting flexible large-diameter shafts during machining. Custom long-bed versions are sometimes quoted for applications requiring more than 1,800 mm of turning length.

04 What tooling does the 12-position turret use?

The QTN-550-II uses a VDI 80 turret interface — the largest standard VDI designation, providing maximum rigidity for heavy roughing operations. Most major tooling manufacturers (Sandvik, Kennametal, ISCAR, Walter) offer VDI 80 compatible toolholders.

05 Does the QTN-550-II come with high-pressure coolant?

The NEXUS-II generation machines ship with high-pressure coolant preparation as standard. The full high-pressure coolant system is typically included or available as a low-cost option, delivering coolant through the turret directly to the cutting edge at 70 bar (1,000 psi) or higher depending on the pump configuration specified.