Studer S121
Key Specifications
X Travel
Z Travel
Max Spindle
Spindle Power
max travel speed x
max travel speed z
How much does the Studer S121 cost?
Estimated price range
Our best estimate for a cnc grinding machine in this class — not a quote from United Grinding (Studer). Configuration moves it a long way.
Overview
The Studer S121 is a compact CNC cylindrical grinding machine with equal travels of 350 mm (13.8 inch) in X and Z and a spindle speed range that reaches 120,000 rpm. It holds workpieces up to 300 mm (11.8 inch) long, 360 mm in diameter and 100 kg (220 lbs) on a 200 mm (7.9 inch) center height.
A top speed of 120,000 rpm only makes sense with very small wheels, so this is first a machine for bores, where the wheel has to reach cutting speed inside a hole a few millimetres across. At the other end of the scale the table allows a grinding wheel up to 300 mm (12 inch) in diameter and 32 mm (1.3 inch) wide and a maximum spindle power of 18 kW (24 hp). Those figures cannot belong to the same spindle as the 120,000 rpm rating. Studer's table does not break them down, so get the spindle line-up of the specific build in writing.
The workpiece envelope is short and wide. A part may be 360 mm across but only 300 mm long, the shape of rings, sleeves and flanged components held in a chuck. The B axis has a swiveling range of 180°, and both linear axes run at up to 20,000 mm/min (787 inch/min).
In Studer's range the S131 is the closest neighbour, with the same 350 mm (13.8 inch) of X travel, 400 mm (15.7 inch) of Z and 15 kW (20 hp). The S141 moves up to 425 mm (16.7 inch) of X travel and keeps the 18 kW (24 hp) and 120,000 rpm of this model.
Full Specifications
| Parameter | Value |
|---|---|
| X-Axis Travel | 350 mm (13.8 inch) |
| Max Travel Speed X | 20,000 mm/min (787 inch/min) |
| Z-Axis Travel | 350 mm (13.8 inch) |
| Max Travel Speed Z | 20,000 mm/min (787 inch/min) |
| Spindle Motor Power | 18 kW (24 hp) |
| Max Spindle Speed | 120,000 rpm |
| Max Grinding Wheel Diameter | 300 mm (12 inch) |
| Max Grinding Wheel Width | 32 mm (1.3 inch) |
| Swiveling Range B | 180 ° |
| Workpiece Length | 300 mm (11.8 inch) |
| Workpiece Diameter | 360 mm |
| Max Workpiece Weight | 100 kg (220 lbs) |
| Center Height | 200 mm (7.9 inch) |
Specifications sourced from studer.com — verified 2026-10-03
Strengths & Limitations
Strengths
- Spindle speeds up to 120,000 rpm for very small internal grinding wheels
- Up to 18 kW (24 hp) of spindle power, more than the 15 kW (20 hp) of the S131
- Chucks parts up to 360 mm in diameter on a 200 mm (7.9 inch) center height
- X and Z both travel 350 mm (13.8 inch) at up to 20,000 mm/min (787 inch/min)
- B axis with a 180° swiveling range
Limitations
- Workpiece length is limited to 300 mm (11.8 inch)
- Workpiece weight is limited to 100 kg (220 lbs), a figure a solid part near the 360 mm diameter limit can exceed
- Z travel is 350 mm (13.8 inch), against 400 mm (15.7 inch) on the S131
- Studer's table does not state which spindle delivers 18 kW (24 hp) and which reaches 120,000 rpm
Best For
Frequently Asked Questions
01
Internal grinding of small bores. A small wheel needs a very high rotational speed to reach a workable cutting speed, and 120,000 rpm is the top of the S121's range. The 300 mm (12 inch) wheel diameter and the 18 kW (24 hp) power figure in the same table describe larger, slower spindles.
02
Up to 300 mm (11.8 inch) long, 360 mm in diameter and 100 kg (220 lbs). The center height is 200 mm (7.9 inch). The proportions suit chucked parts that are wider than they are long.
03
Both have 350 mm (13.8 inch) of X travel and reach 120,000 rpm. The S131 has 400 mm (15.7 inch) of Z travel and 15 kW (20 hp), while the S121 has 350 mm (13.8 inch) of Z and 18 kW (24 hp).
04
X and Z each travel 350 mm (13.8 inch), and each has a maximum travel speed of 20,000 mm/min (787 inch/min). The B axis has a swiveling range of 180°.
