Hardinge Kellenberger U300

Est. $500,000 - $800,000 Specs verified 2026-10-03 · kellenberger.com Updated 2026-10-03

Image: kellenberger.com, Hardinge

Key Specifications

machine type

5-axis universal ID/OD grinder

axes

X, Z, Y (vertical), B1, B2 (hydrostatic)

atc spindle speed

Up to 60,000 RPM

tolerance capability

Sub-micron

How much does the Hardinge Kellenberger U300 cost?

Estimated price range

Est.$500,000 - $800,000

Our best estimate for a cnc grinding machine in this class — not a quote from Hardinge. Configuration moves it a long way.

Overview

The Kellenberger U300 is a 5-axis universal grinder for both inside and outside diameters. Its axes are listed as X, Z, a vertical Y, and two rotary axes, B1 and B2, which are hydrostatic. The spindle row is labelled for automatic tool change and runs at up to 60,000 RPM, and the stated tolerance capability is sub-micron.

The axis list is what sets the U300 apart from a conventional two-axis cylindrical grinder. A vertical Y axis lets the wheel move off the centre line of the part, so features that are not concentric with the work axis can be reached without re-clamping. Two B axes give the machine two swivels to work with, which is what allows tapers, faces and bores to be ground in one setup. Hydrostatic bearings have no metal-to-metal contact, and that suits the tolerance class the machine is described for.

A spindle that reaches 60,000 RPM is aimed at small wheels, since a small internal wheel needs high rotational speed to reach a workable surface speed. Beyond that the listed table is thin: there are no travel figures, no part diameter, length or weight limits, no spindle power and no control. Those have to come from a quotation.

Full Specifications

Parameter	Value
Machine Type	5-axis universal ID/OD grinder
Axes	X, Z, Y (vertical), B1, B2 (hydrostatic)
ATC Spindle Speed	Up to 60,000 RPM
Tolerance Capability	Sub-micron

Specifications sourced from kellenberger.com (authorised dealer / distributor, not the manufacturer's own site) — verified 2026-10-03

Strengths & Limitations

Strengths

Five axes, listed as X, Z, a vertical Y, B1 and B2, so inside and outside diameters can be ground in one clamping
The B1 and B2 rotary axes are hydrostatic
Spindle speed of up to 60,000 RPM for small-diameter wheels
Tolerance capability is stated as sub-micron

Limitations

No travels and no workpiece diameter, length or weight limits are listed, so capacity cannot be judged from the table
Spindle power and the control are not stated
Sub-micron is given as a class, not as a measured roundness or positioning figure

Best For

Combined ID and OD grinding in a single setup Small bores that need wheel speeds up to 60,000 RPM Features off the work axis, reached with the vertical Y axis Parts held to sub-micron tolerances

Frequently Asked Questions

01 What axes does the Kellenberger U300 have?

Five: X, Z, a vertical Y axis and two rotary axes, B1 and B2. The B1 and B2 axes are listed as hydrostatic. The machine type is given as a 5-axis universal ID/OD grinder, meaning it grinds both internal and external diameters.

02 How fast is the U300 spindle?

The spindle with automatic tool change is listed at up to 60,000 RPM. That speed is suited to small wheels for internal grinding. No power or torque figure is published with it, so ask for the spindle data sheet if the work involves heavier stock removal.

03 What accuracy can the U300 hold?

The table states the tolerance capability as sub-micron and gives no roundness, resolution or positioning value behind it. For a part with a specific tolerance, ask for measured results on a comparable workpiece instead of relying on the class alone.