Industrial Heat Treatment of Steel Components: Hardening, Nitriding, Vacuum and Induction Processes with Material Testing
Gruppe HEAT Holding GmbH
Herzberg am Harz · Stuhr · Norderstedt · ReinsbergNew on Amplifa
Heat treatment since over 90 years
Gruppe HEAT Holding GmbH is a family-run contract heat treatment specialist with core competencies in industrial heat treatment processes for steel components. The range of services includes hardening and tempering under protective gas and vacuum, case hardening, carbonitriding, carburizing, gas and plasma nitriding, induction hardening, annealing processes, baining, vacuum hardening, and cryogenic treatment. The processes are supplemented by surface treatments such as abrasive blasting, component cleaning, lapping, insulating, and straightening, as well as material science testing at institute level, including hardness testing, metallography, SEM, X-ray diffractometry, residual contamination, and spectral analyses. The company supports customers from process development for individual parts to large series production. Customers originate from aerospace, automotive industry, food and furniture industry, construction and agricultural machinery, rail and railway transport, medical technology, and mechanical engineering. The group consists of four locations in Germany: Herzberg am Harz (Holding and production), Stuhr and Norderstedt (Gruppe HEAT STUHR GmbH), and Reinsberg (Gruppe HEAT SACHSEN GmbH). Each location is secured by an identically constructed backup heat treatment system within the group.
- Site
- Herzberg am Harz
- Processes
- Hardening and Tempering / Annealing (Protective gas/vacuum), Case Hardening / Carbonitriding / Carburizing, Nitriding (Gas/Plasma), Induction Hardening and Induction Annealing, Annealing (Normal annealing, stress-relieving annealing, soft annealing, solution annealing, flash, Bainitizing, Vacuum Hardening / Vacuum Annealing, Cryogenic Treatment
- Materials
- Steels (demanding steels for cryogenic treatment), Tool steels, Steels (Protective gas/vacuum), Case Hardening / Carbonitriding / Carburizing, Nitriding (Gas/Plasma), Induction Hardening / Induction Annealing, Bainitizing, Vacuum Hardening / Vacuum Annealing
- Certificates
- IATF 16949:2016, DIN EN ISO 50001:2018, DIN EN ISO 14001:2015
- Founded
- 1933
- Industries
- Aerospace, Automotive Industry, Food Industry, Furniture Industry, Construction and Agricultural Machinery, Rail and Railway Transport
- 01
Process development (material and process consulting, component optimization)
- 02
Component cleaning / Blasting / Lapping
- 03
Heat treatment (Hardening, nitriding, vacuum, induction, baining)
- 04
Surface finishing (Insulating, straightening, finishing via partner network)
- 05
Material testing and sorting
- 06
Packaging and logistics
Materials and Heat Treatment Processes
Steels (Protective gas/vacuum)
Hardening, tempering, and annealing to optimize strength and toughness.
Case Hardening / Carbonitriding / Carburizing
Increase in surface hardness and wear resistance with a tough core.
Nitriding (Gas/Plasma)
Improve corrosion and wear resistance with high dimensional stability.
Induction Hardening / Induction Annealing
Localized surface hardening and targeted heat treatment of specific component areas.
Bainitizing
Increasing strength and toughness with optimized tempering.
Vacuum Hardening / Vacuum Annealing
For precision components with high demands on dimensional stability, cleanliness, and surface condition.
Cryogenic Treatment
Complete martensite transformation and retained austenite reduction in demanding steels and tool steels.
Annealing
Normal, stress-relieving, soft, solution, and flash annealing for microstructure homogenization and improved machinability.
Locations of Gruppe HEAT
Herzberg am Harz
DEHolding and production
- Lot size
- Individual parts to large series
- Materials
- Steels
- Endogas system
- Bainitizing system
- Backup heat treatment system
- Solvent-based cleaning system (closed system)
Stuhr
DEProduction (Gruppe HEAT STUHR GmbH)
- Backup heat treatment system
Norderstedt
DEFacility (Gruppe HEAT STUHR GmbH)
- Backup heat treatment system
Reinsberg
DEProduction (Gruppe HEAT SACHSEN GmbH)
- Backup heat treatment system
Industries
Processes & technical limits
| Processes | Tolerance | Max. part | Weight | Lot size | Materials |
|---|---|---|---|---|---|
| Hardening and Tempering / Annealing (Protective gas/vacuum)Heat Treatment | – | – | – | Individual parts – Large series | Steels |
| Case Hardening / Carbonitriding / CarburizingHeat Treatment | – | – | – | – | – |
| Nitriding (Gas/Plasma)Heat Treatment | – | – | – | – | – |
| Induction Hardening and Induction AnnealingHeat Treatment | – | – | – | – | – |
| Annealing (Normal annealing, stress-relieving annealing, soft annealing, solution annealing, flashHeat Treatment | – | – | – | – | – |
| BainitizingHeat Treatment | – | – | – | – | – |
| Vacuum Hardening / Vacuum AnnealingHeat Treatment | – | – | – | – | – |
| Cryogenic TreatmentHeat Treatment | – | – | – | – | Demanding steels, Tool steels |
| Hardening with oil or salt quenchingHeat Treatment | – | – | – | – | – |
| Blasting (Cleaning blasts)Surface | – | – | – | – | – |
| Component Cleaning (chemical and mechanical)Surface | – | – | – | – | – |
| LappingSurface | – | – | – | – | – |
| Surface Finishing (Blackening, galvanizing, coating) via partner networkSurface | – | – | – | – | – |
| Insulating (Partial covering for localized protection during heat treatment)Surface | – | – | – | – | – |
| Straightening (Restoring dimensional stability)Surface | – | – | – | – | – |
| Hardness & Profile Testing (Rockwell, Brinell, Vickers)Testing | – | – | – | – | – |
| Tensile, Compression, and Bending TestsTesting | – | – | – | – | – |
| MetallographyTesting | – | – | – | – | – |
| Residual Contamination Analysis (according to VDA standards)Testing | – | – | – | – | – |
| Spectral Analyses (chemical material analysis)Testing | – | – | – | – | – |
| Salt Spray TestsTesting | – | – | – | – | – |
| Eddy Current TestingTesting | – | – | – | – | – |
| Magnetic Powder TestingTesting | – | – | – | – | – |
| Scanning Electron Microscopy (SEM)Testing | – | – | – | – | – |
| X-ray Diffractometry (Retained austenite content, residual stresses, phase analysis)Testing | – | – | – | – | – |
| 3D Coordinate Measuring (manual)Testing | – | – | – | – | – |
| Surface metrology (Roughness measurement)Testing | – | – | – | – | – |
| Sorting work (Visual inspection and eddy current testing)Testing | – | – | – | – | – |
| Process development (Material and process consulting, component optimization, prototype development)Engineering | – | – | – | – | – |
| Packaging and logistics conceptsEngineering | – | – | – | – | – |
4 Anlagen & Maschinen
| Machine | Manufacturer / model | Quantity | Working area | Year built | Site |
|---|---|---|---|---|---|
| Endogas system | – | – | – | – | – |
| Bainitizing system | – | – | – | – | – |
| Solvent-based cleaning system (closed system) | – | – | – | – | – |
| Backup heat treatment system (identically constructed system per site) | – | 4 | – | – | Herzberg, Stuhr, Norderstedt, Reinsberg |
Additional services
Quality and Certification
Every step of the process is documented and integrated into the customer's quality assurance. The testing technology includes hardness testing (Rockwell, Brinell, Vickers), metallography, SEM, X-ray diffractometry, eddy current and magnetic particle inspection, residual contamination analysis according to VDA standards, and 3D coordinate measuring.
| Evidence | Herzberg am Harz | Stuhr | Norderstedt | Reinsberg |
|---|---|---|---|---|
| IATF 16949:2016 | ||||
| DIN EN ISO 50001:2018 | ||||
| DIN EN ISO 14001:2015 |
Company History
- 1933
Foundion of Fritz Junge Feilenhauerei in Auerbach/Saxony.
- 1958
Relocation to Herzberg with a small salt bath.
- 1972
New construction with salt bath, heat treatment, and start in the automotive sector.
- 1976–1980
Expansion of 2 production halls and setup of heat treatment with gas, plasma, and vacuum.
- 1996
Acquisition of Härtereitechnik Bremen GmbH in Stuhr.
- 1997–1999
Construction of a new plant in Norderstedt.
- 1998–2001
Rebranding to Gruppe HEAT; certification DIN EN ISO 9001 and VDA 6.1.
- 2003
Transfer of management to Paola Schrader-Gerdes.
- 2004
Establishment of Gruppe HEAT Sachsen GmbH.
- 2007
Foundion of BEATERS GmbH for hammer mill production.
- 2011–2019
HEAT Group L.S. (Isıl İşlem San. Ve Tic. Ltd. Sti.).
- 2013
Foundion of Gruppe HEAT Holding GmbH.
- 2023
Timo Schrader-Gerdes and Paul-Ramon Proksch become Managing Directors of Gruppe HEAT Herzberg GmbH.