Studer S131
Key Specifications
axes
max bore diameter
max workpiece diameter at chuck
max workpiece length
max workpiece weight
wheelhead swivel
Overview
The Studer S131 is a large-capacity universal internal cylindrical grinding machine designed for precision internal grinding of large-diameter bores, faces, and profiles in heavy workpieces including large dies, flanges, housings, ring gears, and structural aerospace and energy components. It extends the internal grinding envelope beyond the S121 to accommodate workpieces that require heavy-duty internal grinding capability.
The S131 handles workpieces up to 630 mm (24.8 in) in diameter at the chuck, with bore diameters up to 400 mm (15.7 in) and a maximum workpiece weight of 300 kg (661 lb). Workpiece length is accommodated up to 500 mm (19.7 in). The B-axis wheelhead swivels ±30 degrees for angular and taper internal grinding without workpiece repositioning, and the C-axis workhead provides full rotational control for face grinding and profiled bore operations.
The internal grinding spindle is available in speed configurations up to 40,000 rpm, appropriate for the larger bore diameter range the S131 targets. A face grinding spindle is optionally integrated for simultaneous face and bore grinding in a single setup. The machine is built on a Granitan mineral casting base, which provides superior vibration damping compared to cast iron for the heavy workpiece loads the S131 encounters.
All linear axes operate on Studer's StuderGuide hydrostatic and aerostatic guideway technology. The control system is StuderWIN with StuderGRIND software on a Fanuc CNC platform, with programming modules specific to large-bore and profiled internal grinding.
New Studer S131 machines are typically priced in the $500,000-$750,000 range. Used units are rarely available and price on a case-by-case basis.
Full Specifications
| Parameter | Value |
|---|---|
| Axes | 4 (X, Z linear + C workhead rotation, B wheelhead swivel) |
| Max Bore Diameter | 400 mm (15.7 in) |
| Max Workpiece Diameter At Chuck | 630 mm (24.8 in) |
| Max Workpiece Length | 500 mm (19.7 in) |
| Max Workpiece Weight | 300 kg (661 lb) |
| Wheelhead Swivel | ±30 degrees |
| Internal Spindle Max Speed | 40,000 rpm |
| Guideway System | StuderGuide hydrostatic/aerostatic |
| Base Material | Granitan mineral casting |
| Machine Dimensions | 4,200 x 2,200 x 2,100 mm (165.4 x 86.6 x 82.7 in) |
| CNC Control | StuderWIN with StuderGRIND on Fanuc CNC |
| From | To |
| Newark New York | Las Vegas (LAS) |
| San Francisco | Newark/New York (EWR) |
| Los Angeles | Newark/New York (EWR) |
Strengths & Limitations
Strengths
- 300 kg workpiece capacity and 630 mm chuck diameter handle large aerospace flanges, ring gears, and heavy die components that the S121 cannot reach
- Granitan mineral casting base delivers 6-8x better vibration damping than cast iron, critical when grinding large-diameter bores in heavy workpieces
- 400 mm maximum bore diameter covers ring gear bores, large bearing housings, and heavy industrial component bores in a single specialized machine
- ±30-degree wheelhead swivel maintains the S121's angular and taper capability scaled up to the S131's larger workpiece envelope
- Optional integrated face grinding spindle enables bore-and-face combinations in one setup, eliminating rechucking errors for flanged components
- StuderGuide hydrostatic guideways maintain precision under the high grinding forces generated when material removal rates are maximized on large bores
Limitations
- Machine weight and footprint of 4,200 x 2,200 mm requires heavy foundation work and adequate crane capacity (300 kg workpiece plus tooling requires significant lifting equipment)
- Price range of $500,000-$750,000 new places it among the highest-cost dedicated internal grinders and requires a defined high-value application to justify
- 40,000 rpm maximum internal spindle speed is appropriate for mid-range bores but limits the machine for very small bore diameters — the S121 with its 60,000 rpm option is better for micro bores
- Highly specialized machine — shops without a consistent flow of large-diameter internal grinding work will find the S131 difficult to justify
- Used market is extremely thin; when units do appear they are older machines with limited remaining precision life
Best For
Frequently Asked Questions
01
The S131 is a larger-capacity version of the S121 internal grinder. Key differences: the S131 handles workpieces up to 300 kg (vs. 150 kg for S121), bores up to 400 mm diameter (vs. 250 mm), workpieces up to 630 mm at the chuck (vs. 400 mm), and longer parts up to 500 mm. The S131 uses a Granitan mineral casting base for enhanced damping under heavier workloads. The S121 achieves higher spindle speeds (60,000 rpm) for micro-bore applications that the S131 doesn't target.
02
The S131 grinds any material that can be internal cylindrically ground: hardened tool steels, stainless steel, titanium, nickel superalloys, aluminum, cast iron, and ceramics with appropriate wheel selection. Large-diameter bores in hardened steel and aerospace alloys are the machine's primary application space. Grinding parameters and wheel specifications change significantly across these materials, and Studer's applications team can provide process recommendations for specific material-bore combinations.
03
New Studer S131 machines are typically priced between $500,000 and $750,000 depending on spindle configuration, optional face grinding spindle, automation integration, and measuring system. This is a highly specialized machine for large-component internal grinding, and the price reflects its heavy-duty construction and precision capability. Used units are rarely available; when they appear, pricing is negotiated based on condition and age.
04
Yes. The S131 supports integration with portal loaders and gantry systems for large workpiece handling. Given the 300 kg workpiece weight capacity, automation is often a practical necessity for production environments. Studer's engineering team works with customers to design appropriate loading solutions for the specific workpiece weights and geometries involved.
Videos
UNITED GRINDING North America
UNITED GRINDING North America
UNITED GRINDING North America
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