Stama MC 531/Mill-Turn

$900,000 - $1,400,000 Updated 2026-03-17

Key Specifications

X Travel

530 mm per station (1,060 mm combined)

Y Travel

430 mm (16.9 in)

Z Travel

380 mm (15 in)

Spindle Taper

HSK-A50

Tool Capacity

2 × 40 (80 total)

Rapid Traverse

60 m/min (2,362 ipm)

Overview

The Stama MC 531/Mill-Turn is a twin-spindle mill-turn machining center that extends the proven MC 531 platform with full turning capability — adding a torque-optimized spindle mode, B-axis for off-centerline tool positioning, and live turning routines to the machine's existing 5-axis milling repertoire. The result is a machine capable of producing complex rotational components with prismatic milled features in a single setup, eliminating the traditional handoff between turning and machining centers that adds lead time, re-chucking error, and logistical complexity to complex part production.

In mill-turn mode, the MC 531/Mill-Turn clamps a workpiece in a chuck or collet on the A-axis trunnion and rotates it under a stationary or interpolating milling/boring tool — combining turning kinematics with the machine's 5-axis milling structure. For milling operations, the spindle returns to high-speed cutting mode. The B-axis (tool tilt) enables oblique turning, back-turning, and eccentric boring operations that would otherwise require multiple setups. This architecture is well-suited to complex components like landing gear actuator pistons, hydraulic cylinder bodies, fuel injector housings, and aerospace shaft-type components with both turned diameters and milled features.

The twin-spindle configuration maintains the MC 531 productivity principle: two identical machining units operate simultaneously on two parts. In mill-turn production, both stations execute the same sequence — turning diameter A, milling pocket B, boring cross-hole C — simultaneously. A synchronized gantry or robot loads and unloads both stations in one automation cycle. For sufficiently complex rotational parts, the MC 531/Mill-Turn offers a compelling alternative to two separate mill-turn lathes.

The machine is built at Stama's Schlierbach, Germany facility and is controlled via Siemens Sinumerik 840D sl with the full 5-axis and turning cycle package. Integration with Stama and Chiron automation systems — including twin-station robot cells — enables unmanned or lights-out operation. The MC 531/Mill-Turn targets aerospace, automotive, and hydraulic component manufacturers whose parts demand both turning precision and 5-axis milling access.

Full Specifications

Parameter	Value
Spindle Count	2 (twin mill-turn units)
X-Axis Travel	530 mm per station (1,060 mm combined)
Y-Axis Travel	430 mm (16.9 in)
Z-Axis Travel	380 mm (15 in)
A Axis Swivel	-120° / +30° (trunnion + chucking)
B Axis Tool Tilt	±90° (mill-turn head)
C Axis Spindle	360° continuous (turning interpolation)
Spindle Speed Milling	18,000 RPM (milling mode)
Spindle Speed Turning	1,200 RPM max (turning mode)
Spindle Taper	HSK-A50
Spindle Motor Power	2 × 22 kW (2 × 29.5 hp)
Turning Torque	2 × 180 Nm at chuck (2 × 133 ft-lb)
Rapid Traverse Rate	60 m/min (2,362 ipm)
Tool Capacity	2 × 40 (80 total)
Workpiece Size Max	300 mm diameter × 400 mm length per station
CNC Control	Siemens Sinumerik 840D sl

Strengths & Limitations

Strengths

Combines 5-axis milling and turning in a twin-spindle platform — a rare configuration that enables complete machining of complex rotational components without any inter-machine transfer
Twin simultaneous machining of mill-turn parts doubles output vs. a single-spindle mill-turn center at lower floor space and automation cost than two separate machines
B-axis tool tilt enables oblique turning, back-turning, and eccentric boring operations that single-axis mill-turn machines cannot perform, expanding the range of completable geometries
18,000 RPM milling spindle provides full high-speed milling capability — the machine does not compromise milling performance to add turning, unlike some integrated platforms
Chiron Group global service network provides high-uptime production support for automotive and aerospace manufacturing customers with strict SLA requirements

Limitations

1,200 RPM maximum turning speed limits cutting speed for small-diameter turning on steel and stainless — dedicated turning centers with 4,000–6,000 RPM achieve higher surface footage on small diameters
Very high capital cost demands consistent high-volume production of complex mill-turn parts to generate a cost-per-part advantage — the investment is difficult to justify for low-volume or mixed-family production
Twin-spindle mill-turn programming is among the most complex NC setups in manufacturing — requires advanced CAM, experienced programmers, and Stama applications support for initial part development

Best For

Aerospace Tier 1 suppliers producing complex rotational components — actuator pistons, hydraulic valve bodies, fitting shanks — requiring precision turned diameters and 5-axis milled features in a single setup Automotive powertrain manufacturers producing camshafts, crankshaft-adjacent components, and complex housing components with both high-precision turning requirements and milled port or pocket features Hydraulic and fluid power manufacturers machining complex cylinder bodies, valve spools, and manifold sections in medium-to-high volumes where single-setup accuracy is critical Defense and energy manufacturers producing complex shaft and housing families from titanium, Inconel, and high-alloy steels where setup reduction directly translates to tolerance capability

Frequently Asked Questions

01 How does the MC 531/Mill-Turn differ from a traditional mill-turn lathe?

A traditional mill-turn lathe (like the Mazak Integrex or DMG Mori NTX series) is built on a lathe platform with milling added — the primary machine axis is a turning spindle, and the milling head is secondary. The MC 531/Mill-Turn is built on Stama's 5-axis VMC platform with turning capability added — the primary structure is a machining center bridge, and the turning function is achieved through A-axis chucking and interpolated C-axis rotation. The result emphasizes 5-axis milling precision, with turning as a complementary capability rather than the primary function.

02 What turning diameter and length can the MC 531/Mill-Turn accommodate?

The machine accommodates turned diameters up to approximately 300 mm and turned lengths up to 400 mm per station. These dimensions reflect the A-axis trunnion envelope — parts must fit within the 300 × 300 × 300 mm machining envelope while allowing clearance for turning tool paths. Larger shaft or housing components would exceed the work envelope and require a larger mill-turn platform.

03 Can the two stations run different mill-turn programs simultaneously?

No. The MC 531/Mill-Turn operates both stations synchronously on identical programs — the productivity model requires both stations to machine identical parts simultaneously. If your production requires different parts on each station, a standard single-spindle mill-turn center or a flexible pallet HMC would be more appropriate. The twin-spindle advantage only applies to uniform part families.

04 What CAM software is recommended for the MC 531/Mill-Turn?

Full 5-axis mill-turn CAM capability is required. Siemens NX CAM, Hypermill (Open Mind), Mastercam Mill-Turn, and Vericut are all used in production environments. The twin-spindle synchronized output requires a post-processor that generates paired programs for both stations — Stama's applications team provides verified post-processors and setup templates for the most common CAM systems.

05 What is the lead time and delivery window for the MC 531/Mill-Turn?

As a configured twin-spindle mill-turn machine built in Germany, lead times are typically 10–16 months from order to delivery depending on the automation package selected and Stama's order backlog. Early engagement with Stama's applications team — 12–18 months before required production start — is recommended for automotive programs with hard launch dates. Stama's sales offices in Europe and North America (via Chiron America) manage customer projects from specification through commissioning.