Hardinge Kellenberger K8
Key Specifications
X Travel
Z Travel
Max Workpiece ⌀
center distance
center height
max workpiece length
Overview
The Hardinge Kellenberger K8 is the entry-level model in the Kellenberger K-series cylindrical grinding platform, designed to bring Swiss-precision OD/ID grinding capability to shops that need Kellenberger quality at an accessible price point. Positioned below the K10 in the lineup, the K8 offers a compact footprint with center distances suited for smaller workpieces while maintaining the core precision and build quality that define the Kellenberger brand.
The K8 features a 650 mm center distance with 175 mm center height, accommodating workpieces up to 350 mm diameter and 650 mm length. The external grinding spindle delivers 5.5 kW of power through a water-cooled motor driving grinding wheels up to 400 x 50 mm at peripheral speeds of 50 m/s. The workpiece headstock provides infinitely variable speeds from 1 to 1,000 RPM. An optional high-frequency internal grinding spindle reaches speeds up to 60,000 RPM for precision bore grinding, making the K8 a versatile ID/OD platform despite its compact size.
Axis travels include 800 mm on Z and 310 mm on X, with feed rates of 20,000 mm/min and 10,000 mm/min respectively. Scale resolution of 0.00001 mm (10 nanometers) on both axes reflects the sub-micron positioning capability expected in precision cylindrical grinding. The machine structure uses a mineral-cast or cast-iron base for vibration damping, with linear roller guideways for smooth, precise axis motion.
The K8 runs on a Fanuc 0i-F Plus CNC control with a 19-inch touchscreen interface and Kellenberger's BLUE Solution grinding software, which simplifies programming for both experienced grinder operators and CNC machinists transitioning to grinding. New K8 machines price between $180,000 and $280,000. The machine competes with the Studer S33, Junker Jumat, and Toyoda GL4Ai-63 in the entry-level precision cylindrical grinder segment.
Full Specifications
| Parameter | Value |
|---|---|
| Center Distance | 650 mm (25.6 in) |
| Center Height | 175 mm (6.9 in) |
| Max Workpiece Diameter | 350 mm (13.8 in) |
| Max Workpiece Length | 650 mm (25.6 in) |
| Max Workpiece Weight | 80 kg (176 lb) |
| Z-Axis Travel | 800 mm at 20,000 mm/min |
| X-Axis Travel | 310 mm at 10,000 mm/min |
| Axis Resolution | 0.00001 mm |
| External Grinding Wheel | 400 x 50 mm |
| Peripheral Speed | 50 m/s |
| External Motor Power | 5.5 kW (water-cooled) |
| Workpiece Speed Range | 1 - 1,000 RPM |
| Internal Grinding Speed | Up to 60,000 RPM (optional) |
| Internal Grinding Power | 5.5 kW max |
| CNC Control | Fanuc 0i-F Plus |
| Machine Weight | 3,200 kg (7,055 lb) |
| Floor Space Required | 2.8 x 2.0 m |
Specifications sourced from kellenberger.com — verified 2026-03-28
Strengths & Limitations
Strengths
- Entry point to Kellenberger Swiss-precision grinding at a lower investment than the K10 or K100 platforms
- 10-nanometer axis resolution delivers the sub-micron positioning accuracy required for precision cylindrical grinding
- Optional internal grinding spindle up to 60,000 RPM enables combined OD/ID grinding on a single machine
- Fanuc 0i-F Plus with BLUE Solution software simplifies grinding cycle programming for operators transitioning from turning or milling
- Compact 2.8 x 2.0 m footprint fits into shops with limited floor space without sacrificing grinding precision
- Water-cooled grinding motor maintains thermal stability during extended production runs
Limitations
- 650 mm center distance limits workpiece length compared to the K10's 1,000 mm, restricting long-shaft grinding applications
- 5.5 kW external grinding power is lower than the K10's 7.5 kW, limiting material removal rates on larger diameters
- Entry-level positioning in the Kellenberger lineup means fewer configuration options than the K100 or K1000
- Kellenberger grinders command a premium over Asian-manufactured alternatives, which may be difficult to justify for general-purpose grinding
Best For
Frequently Asked Questions
01
New Kellenberger K8 machines price between $180,000 and $280,000 depending on configuration. Base machines with external grinding only start near $180,000. Adding internal grinding spindle, dressing systems, in-process gauging, and automation options pushes prices toward $280,000.
02
The K10 steps up with 1,000 mm vs 650 mm center distance, 200 mm vs 175 mm center height, 7.5 kW vs 5.5 kW grinding motor, and larger 400 x 63 mm or 500 x 80 mm wheel options. Both share the same Fanuc control and BLUE Solution software. Choose the K8 for shorter workpieces where the compact footprint is valued; choose the K10 for longer shafts and higher material removal rates.
03
Yes, with the optional high-frequency internal grinding spindle. The internal spindle reaches speeds up to 60,000 RPM with up to 5.5 kW power, enabling precision bore grinding. This makes the K8 a combined OD/ID grinding platform capable of completing most cylindrical grinding operations in a single setup.
04
BLUE Solution is Kellenberger's proprietary grinding software that runs on the Fanuc CNC platform. It provides guided programming for common grinding cycles including plunge, traverse, shoulder, and taper grinding. The software simplifies setup for operators who may not have extensive grinding programming experience while still allowing advanced customization for complex grinding operations.
Videos
Kellenberger
