Punching plant for electrical steel laminations: production of flat stamped parts, stamped-bent parts and lamination stacks for transformers, motors and electronics.
Erich Grau GmbH
Sersheim (Baden-Württemberg), GermanyNew on Amplifa
Punching technology is our world
Founded in Sersheim in 1952, Erich Grau GmbH is an internationally active family-owned company in the field of punching technology. The production program includes flat stamped and stamped-bent parts made of electrical steel strip, cold-rolled and slit strip, and stainless steel, in particular transformer core laminations, stator and rotor laminations for electric motors, lamination stacks and stamped-bent parts from small batches to large-scale series. Core competencies are the stacking operation (riveted, welded, bonded, interlock-stacked and backlack-baked stacks), in-house toolmaking with its own design department, sample and prototype production, as well as laser cutting, powder coating for slot insulation and annealing for magnetic improvement. More than 150 employees work on over 10.000 m² of production floor space with more than 30 high-speed punching presses in three-shift operation. Products are used, among other things, in the electrical and automotive industries, mechanical engineering, and HVAC and building technology.
- Site
- Sersheim
- Processes
- Punching (flat stamped parts, stamped-bent parts, formed parts), Laser cutting, Laser cutting (samples/prototypes), Laser welding (stacking), Interlock stacking, Riveting of lamination stacks, Welding of lamination stacks, Bonding of lamination stacks
- Materials
- Electrical steel strip / electrical steel sheet per DIN EN 10106 / EN 10107 (non-grain-oriented), Grain-oriented electrical steel strip per EN 10107, M 140-30 S, M 150-30 S, M 150-35 S, M 165-35 S, M 103-27 P, M 105-30 P
- Certificates
- ISO 9001:2015
- Founded
- 1952
- Employees
- >150
- Industries
- Automotive, Drive technology, Stator and rotor technology, Medical technology, Electrical industry, Aerospace
- 01
Toolmaking/Design
- 02
Punching
- 03
Laser cutting (samples/small batches)
- 04
Stacking (riveting, welding, bonding, interlock stacking, backlack)
- 05
Annealing for magnetic improvement
- 06
Powder coating/Surface
- 07
Injection molding (plastic overmolding)
- 08
Testing/Logistics
Materials and processes
Electrical steel strip 1.0862 (M 140-30 S)
Non-grain-oriented electrical steel strip per DIN EN 10106 for transformer and motor laminations.
Electrical steel strip 1.0817 (M 800-50A)
Non-grain-oriented electrical steel strip for lower-power mains transformers.
Electrical steel strip 1.0829 (M 1000-65A)
Cost-efficient electrical steel strip grade per DIN EN 10106.
Grain-oriented electrical steel strip (EN 10107)
Low watt losses for high-power, low-volume applications.
Cold-rolled and slit strip
Base material for stamped and stamped-bent parts of all kinds.
Stainless steel
For stamped parts with corrosion resistance requirements.
Carbide (toolmaking)
Cutting elements in high-performance progressive stamping dies for long tool life.
Plastic (injection molding)
For plastic-overmolded lamination stacks (plastic meets metal).
Locations
Sersheim
DEMain plant: administration, punching operation, stacking operation, toolmaking, laser cutting, powder coating,
- Lot size
- Single piece to large-scale series
- Materials
- Electrical steel strip, cold-rolled/slit strip, stainless steel, plastic
- >30 punching presses (10–250 t, up to 700 strokes/min., three-shift operation)
- Bihler stamping-bending machines
- Laser cutting systems (CO2 slab laser, fiber laser, max. 1,250 × 2,500 mm)
- Laser welding systems (ND:YAG/diode lasers up to 1 kW)
- Powder coating line (longitudinal transfer)
- 2 injection molding machines
- 3D and CNC coordinate measuring machines
- High-bay warehouse with approx. 2,500 storage slots
Components
Inside the production
Industries
Processes & technical limits
| Processes | Tolerance | Max. part | Weight | Lot size | Materials |
|---|---|---|---|---|---|
| Punching (flat stamped parts, stamped-bent parts, formed parts)Forming | – | – | – | Small batch – Large-scale series | Electrical steel strip, Cold-rolled strip, Slit strip, Stainless steel |
| Laser cuttingMachining | ±0.03mm | 1.250 x 2.500 mm | – | Single piece – Large-scale series | Sheet metal 0.1–2.0 mm, Sheet and strip material |
| Laser cutting (samples/prototypes)Machining | ±0.03mm | 1.250 x 2.500 mm | – | – | Sheet metal 0.1 mm - 2.0 mm |
| Laser welding (stacking)Joining | – | – | – | – | Electrical steel sheet, Different materials for stacks |
| Interlock stackingJoining | – | – | – | Large-scale series | Electrical steel sheet |
| Riveting of lamination stacksJoining | – | – | – | – | Electrical steel sheet |
| Welding of lamination stacksJoining | – | – | – | – | Electrical steel sheet |
| Bonding of lamination stacksJoining | – | – | – | – | Electrical steel sheet |
| Baking of lamination stacks with backlackJoining | – | – | – | Samples/small batch | Backlack-insulated electrical steel sheet |
| Wire EDMMachining | – | – | – | – | Carbide, Steel (toolmaking) |
| Grinding (toolmaking, grinding of pole faces)Machining | – | – | – | – | – |
| Milling (toolmaking)Machining | – | – | – | – | – |
| Toolmaking (progressive stamping dies, stamping-bending tools)Engineering | – | – | – | – | Carbide |
| Sample and prototype productionEngineering | – | – | – | Single part – Small batch | Electrical steel sheet |
| Powder coating (slot insulation, electrostatic)Surface treatment | Coating thickness 200 - 400 µm | – | – | Small batch – Large-scale series (fully automatic) | Armature and stator stacks, Lamination stacks |
| KTL coatingSurface treatment | – | – | – | – | Lamination stacks |
| Cut-edge coatingSurface treatment | – | – | – | – | Lamination stacks |
| ElectroplatingSurface treatment | – | – | – | – | Lamination stacks |
| PhosphatingSurface treatment | – | – | – | – | Lamination stacks |
| BluingSurface treatment | – | – | – | – | Lamination stacks |
| Annealing for magnetic improvement / stress-relief annealing (approx. 820°C, 1 h, N2 protective gas)Heat treatment | – | – | – | – | Electrical steel sheet, Grain-oriented electrical steel strip |
| Injection molding (plastic overmolding of lamination stacks)Plastics | – | – | – | – | Lamination stacks, Plastic |
| Grinding of pole facesMachining | – | – | – | – | Core lamination stacks |
| Producing and finish-turning of boresMachining | – | – | – | – | Core lamination stacks |
| Press-fitting of short-circuit ringsJoining | – | – | – | – | Core lamination stacks |
10 Anlagen & Maschinen
| Machine | Manufacturer / model | Quantity | Working area | Year built | Site |
|---|---|---|---|---|---|
| High-speed punching presses | – | über 30 | 10-250 t pressing force, up to 700 strokes per minute | – | Sersheim |
| Bihler stamping-bending machines | Bihler | – | – | – | Sersheim |
| Laser cutting systems (CO2 slab lasers and fiber lasers) | – | – | Cutting area max. 1.250 x 2.500 mm | – | Sersheim |
| Laser welding systems (ND:YAG solid-state and diode lasers) | – | – | Powers up to 1 kW | – | Sersheim |
| Powder coating line (longitudinal transfer line, fully automatic) | – | – | – | – | Sersheim |
| Manual powder coating systems | – | – | – | – | Sersheim |
| 3D measuring machines and coordinate measuring machine | – | – | – | – | Sersheim |
| Injection molding machine | – | 2 | – | 2015 / 201 | Sersheim |
| CAD systems | – | 3 | – | – | Sersheim |
| High-bay warehouse | – | 1 | ca. 2.500 storage slots | 2003 | Sersheim |
Additional services
Reference customers
Quality
A quality management system certified to ISO 9001:2015 (Bureau Veritas) ensures standardized processes and continuous improvement. For inspection, a measuring room with 3D measuring machines and a CNC coordinate measuring machine is available.
| Evidence | Sersheim |
|---|---|
| ISO 9001:2015 |