Junker JUMAT 5000

$450,000 – $650,000 Updated 2026-03-17

Key Specifications

Max Grinding Length (between centers)

500 mm

Max Workpiece Diameter

200 mm

Center Height

175 mm

Max Workpiece Weight (between centers)

50 kg

External Grinding Wheel Diameter

Up to 500 mm

External Spindle Speed (CBN option)

Up to 120 m/s wheel speed

Overview

The Junker JUMAT 5000 is a CNC universal cylindrical grinding machine from the Junker Group, designed for the high-precision external and internal grinding of shafts, sleeves, and rotationally symmetric components. Junker positions the JUMAT series as a flexible production grinder capable of handling both conventional OD cylindrical grinding and CBN high-speed grinding in a single platform, bridging the gap between flexible job shop machines and dedicated production grinders.

The JUMAT 5000's defining feature is its swiveling wheelhead, which can carry two external grinding spindles — one optimized for conventional abrasive wheels and one for CBN superabrasive wheels at elevated speeds — plus an internal grinding spindle. This configuration allows a single machine to handle a wide range of materials, lot sizes, and grinding strategies without physical reconfiguration between jobs.

Junker builds the JUMAT on a Granitan polymer concrete base (licensed technology similar to Studer's Granitan), providing the thermal and vibration stability that cylindrical grinding demands. Hydrostatic or aerostatic guideway options are available depending on the application's precision requirements. The FANUC-based control system integrates Junker's own JUPITER HMI, which provides cycle-based programming familiar to cylindrical grinding operators.

The JUMAT 5000 is used across automotive driveline and transmission manufacturing, hydraulic component production, aerospace shaft grinding, and fluid power industries. Its ability to switch between conventional and CBN grinding strategies within a single program makes it particularly valuable in mixed-material production environments.

Full Specifications

Parameter	Value
Max Grinding Length (Between Centers)	500 mm
Max Workpiece Diameter	200 mm
Center Height	175 mm
Max Workpiece Weight (Between Centers)	50 kg
External Grinding Wheel Diameter	Up to 500 mm
External Spindle Speed (CBN Option)	Up to 120 m/s wheel speed
Internal Grinding Spindle Speed	Up to 80,000 RPM
Wheelhead Swivel	CNC controlled (B-axis), full 360°
External Spindle Count	2 (conventional + CBN)
Achievable Roundness	< 0.3 µm
Achievable Cylindricity	< 1 µm
Achievable Surface Roughness	Ra < 0.08 µm
X-Axis (Infeed) Resolution	0.0001 mm
Control System	FANUC 31i + Junker JUPITER HMI
Machine Base	Polymer concrete (Granitan equivalent)
Machine Weight	Approx. 7,000 kg

Specifications sourced from junker-usa.com — verified 2026-03-28

Strengths & Limitations

Strengths

Dual external grinding spindles (conventional + CBN) on a single swiveling wheelhead for multi-strategy flexibility
CBN high-speed grinding capability at up to 120 m/s for significantly reduced cycle times on steel parts
Polymer concrete base provides excellent vibration damping and thermal stability
CNC wheelhead swivel (B-axis) allows angular grinding of tapers and shoulders without manual adjustment
FANUC control base provides broad operator familiarity and long-term spare parts availability

Limitations

Higher complexity than fixed-wheelhead cylindrical grinders — more setup considerations
Dual spindle wheelhead increases machine width and may require larger floor space allocation
CBN wheel investment adds to total cost of ownership versus conventional abrasive strategies

Best For

Automotive transmission and driveline shaft manufacturers needing both OD and ID capability Hydraulic cylinder and valve component producers requiring flexible lot-size handling Mixed-material grinding environments where both conventional and CBN strategies are deployed Production cells transitioning from conventional grinding to high-speed CBN for productivity gains

Frequently Asked Questions

01 What is the key advantage of having two external spindles on the JUMAT 5000?

The two external spindles allow the machine to carry both a conventional abrasive wheel (for softer materials, roughing, or shops that prefer conventional grinding) and a CBN superabrasive wheel (for hardened steels at high cutting speeds) simultaneously. The CNC wheelhead swivels between them automatically, so a single program can rough-grind with conventional abrasive and finish-grind with CBN without manual intervention.

02 What is high-speed CBN grinding and how does it benefit production?

CBN (cubic boron nitride) wheels can operate at wheel surface speeds of 80–120 m/s — two to four times faster than conventional abrasive wheels. At these speeds on hardened steel, CBN grinding achieves significantly shorter cycle times, longer wheel life, and better surface integrity (less heat input into the workpiece). The JUMAT 5000's high-speed spindle option supports these speeds.

03 How does the JUMAT 5000 compare to the Studer S31?

Both are universal cylindrical grinders in a similar size class, but they differ in design philosophy. The Studer S31 is a Swiss precision machine with Granitan base and StuderGuide hydrostatic guideways, emphasizing the absolute highest geometric accuracy. The JUMAT 5000 differentiates on production flexibility — particularly its dual external spindle configuration for conventional/CBN switching — making it attractive in high-throughput automotive environments.

04 Can the JUMAT 5000 grind non-round profiles?

With the optional CNC C-axis on the workhead, the JUMAT 5000 can perform non-circular grinding for cam lobes, eccentric pins, and polygon profiles. This requires the C-axis and X-axis to interpolate simultaneously, a capability supported by the FANUC 31i control.

05 What in-process gauging systems are compatible with the JUMAT 5000?

The JUMAT 5000 is compatible with Marposs and Renishaw active gauging systems for in-process diameter measurement and automatic size compensation. Integration is available via the FANUC 31i control's built-in skip signal and measurement compensation functions.