Diezinger

What Diezinger does

Diezinger GmbH is a German Mittelstand manufacturer founded in 1972 and headquartered in Leutershausen, Bavaria, specializing in fire-protection closures (Feuerschutzabschlüsse) and architectural metalwork. Its core products are custom-sized (Sondermaße) doors, gates, flaps, steel-glass elements, and steel-glass facades produced in fire-retardant (FH), fire-resistant (FB) and smoke-tight (RS) variants certified to DIN 4102-5 and DIN 18095, with the additional EN 1090-1:2009 + A1:2011 certification for fabricated steel and aluminum construction products. Manufacturing runs on a ~4,500 m² single-site footprint equipped with CNC milling and drilling centers, stamping and edge-processing lines, and in-house powder coating for corrosion protection and finishing.

The company operates a direct B2B, enterprise field-sales motion targeting two vertical segments: public-sector buildings (schools, hospitals, prisons) and industrial/commercial construction projects. Revenue is generated through one-time sales of certified fire-protection products plus recurring installation, commissioning and maintenance of Feststellanlagen (fixed-setting systems) on fire closures, supplemented by contract-manufacturing services (CNC machining, stamping, powder coating) offered to other industrial buyers. The firm relies on three core system partners — Forster Profile, Jansen, and System Schröders — for profile systems, and serves only the German market from its sole production facility.

Operationally, Diezinger is privately held under sole managing director Petra Diezinger with no external investors or holding-company structure disclosed; the firm employs 50+ qualified personnel and markets itself on "Sicherheit und Qualität vom Fachmann" (Safety and Quality from the Specialist). No quantitative revenue, funding rounds, acquisitions, or international expansion are present in the available source data, consistent with a stable, owner-operated manufacturing business anchored in regulated German construction demand.

Name

Diezinger

Legal name

Diezinger GmbH

Website

https://diezinger-brandschutz.de

Company type

Private

Founded year

1972

Operating status

Operating

Headcount range

11–50 employees

Short description

Diezinger GmbH is a German manufacturer founded in 1972 that produces custom, DIN-certified fire-retardant, fire-resistant, and smoke-tight doors, gates, and facade elements for public buildings and industrial facilities in Germany.

Ownership category

akta.pro rank

Product category

Fire Protection Doors, Gates and Facade Elements

NAICS

Metal Window and Door Manufacturing (332321)

SIC

Metal Doors, Sash, Frames, Moldings & Trim (3442)

akta.pro primary industry

Fire Door, Firestop & Passive Fire Protection Inspection/Installation (IMAIAJAJ)

Keywords

• Fire protection doors
• Smoke-tight closures
• Steel-glass facades
• Industrial metal fabrication
• Powder coating services

Headquarters

HQ city

Leutershausen

HQ country

Germany

HQ region

Europe

Offices1 record

Markets served

GTM type

B2B

Offering type

Hardware or Manufacturing

Cost components

Personnel, Supply Chain, Operations, Infrastructure, Marketing or Sales

Revenue model

1. Fire protection product manufacturing: Manufacturing and sale of fire-retardant, fire-resistant, and smoke-tight doors, gates, and facade elements for buildings
2. Contract manufacturing (Lohnfertigung): Contract manufacturing services including stamping, edge processing, milling, and drilling for other companies
3. Powder coating services: Powder coating services for steel and aluminum elements, providing corrosion protection and surface finishing
4. Installation and maintenance services: Installation, commissioning, and maintenance services for fire protection closures (Feststellanlagen)

Go-to-market motion1 record

Distribution channels1 record

Marketing channels2 records

Core offering

Diezinger GmbH manufactures custom-built fire protection doors, gates, and facade elements in fire-retardant (FH), fire-resistant (FB), and smoke-tight (RS) versions per DIN 4102-5 and DIN 18095. The company produces these in individual custom dimensions (Sondermaße) at its Leutershausen facility and also delivers contract manufacturing services (CNC machining, stamping/edge processing, powder coating) plus installation, commissioning, and maintenance of fire protection closure systems.

Product overview

Diezinger GmbH is a medium-sized manufacturing company specializing in fire protection doors, gates, and facade elements. The product portfolio centers on fire-retarding (FH), fire-resistant (FB), and smoke-proof (RS) products manufactured to DIN 4102-5 and DIN 18095 standards. Core offerings include Drehflügeltüren (swing doors), Schiebetüren (sliding doors), doppelwandige Mehrzwecktüren (double-walled multi-purpose doors), Stahl-Glas-Elemente (steel-glass elements), and Stahl-Glas-Fassaden (steel-glass facades). These are complemented by manufacturing services including CNC machining, stamping/edge processing, and powder coating for surface finishing. Installation, commissioning, and maintenance services for fire protection closures are also provided. All products are custom-manufactured to specifications at the Leutershausen facility.

Differentiator

Problem solved

Functional benefit

Products and services

• Drehflügeltüren, -tore und -klappen FH/FB/RS (Swing doors, gates, and flaps) Swing doors, gates, and flaps in fire-retarding (FH), fire-resistant (FB), and smoke-proof (RS) versions manufactured according to DIN 4102-5 and DIN 18095 standards, custom-built to project specifications.
• Schiebetüren und -tore (Sliding doors and gates) Sliding doors and gates produced for fire protection applications, custom-manufactured at the Leutershausen facility.
• Doppelwandige Mehrzwecktüren (Double-walled multi-purpose doors) Double-walled multi-purpose doors for industrial and commercial use.
• Stahl-Glas-Elemente FH/FB/RS (Steel-glass elements) Steel-glass elements in fire-retarding, fire-resistant, and smoke-proof configurations for architectural applications.
• Stahl-Glas-Fassaden FH/FB/RS (Steel-glass facades) Steel-glass facades with fire protection ratings for building exteriors, built to DIN 4102-5 and DIN 18095 standards.
• Installation, commissioning, and maintenance of Feststellanlagen (fixed-setting systems on fire protection closures) Installation, commissioning, and maintenance services for fixed-setting systems on fire protection closures (Feststellanlagen).
• Stanzen & Kanten (Stamping and edge processing) Contract stamping (Stanzen) and edge processing (Kanten) services for steel and metal components.
• CNC-Fräs- und Bohrbearbeitung (CNC milling and drilling) CNC milling and drilling machining services for precision metal fabrication, available as contract manufacturing (Lohnfertigung) for external companies.
• Pulverbeschichtungen (Powder coating services) Powder coating services for steel and aluminum elements, providing corrosion protection and color finishing for indoor and outdoor applications.

Named customers2 records

Segments2 records

Ideal customer profiles2 records

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature7 records

Partnerships

Three partnerships are on record, tiered core.

• Forster ProfilecoreStrategic or Co-development PartnerForster Profile is a system partner providing profile systems used in Diezinger's fire protection door and gate manufacturing. The partnership enables the company to deliver high-quality fire protection solutions using Forster's profile technology.
• JansencoreStrategic or Co-development PartnerJansen is a system partner supplying profile systems for use in Diezinger's fire protection and steel-glass construction products, enabling the delivery of certified fire protection solutions.
• System SchröderscoreStrategic or Co-development PartnerSystem Schröders is a system partner providing profile systems for fire protection applications. The partnership enables Diezinger to offer comprehensive fire protection solutions using Schröders' proven system technology.

Scale indicators3 records

Recent moves5 records

Expansion highlights3 records

Broad incumbents

• ASSA ABLOY: Global leader in door opening solutions, including certified fire doors and architectural openings. Competes with Diezinger in higher-spec European fire-rated projects as part of a much wider portfolio.
• Hörmann: Germany's largest door and gate manufacturer with an extensive fire-rated product line. Overlaps with Diezinger in fire-rated doors and gates but operates at far greater scale and breadth.

Direct peers

• Teckentrup: German manufacturer of steel doors, industrial doors, and fire-rated closures (FH/FB/RS), with a similar product mix to Diezinger and overlapping public-sector customer base in Germany.
• GEZE: German specialist in door, window, and safety technology, including smoke and fire protection systems and hold-open devices, with overlapping installation and maintenance service offerings.
• Novoferm: German manufacturer of industrial, commercial, and fire-rated doors and gates with broad DIN/EN certifications, directly competing with Diezinger for German and European fire-protection enclosure projects.
• Heuser Feuerschutz: Mid-sized German specialist in fire-rated doors and closures, directly comparable to Diezinger in scale, product focus, and target customer segments in German public and commercial construction.

Regional players

• Wisniowski: Polish manufacturer of doors, gates, and fire-rated enclosures serving Central European construction markets, comparable in product range to Diezinger but with a different geographic focus.
• Ryterna: Lithuanian manufacturer of industrial and commercial doors including fire-rated variants, serving Northern and Eastern European markets with a comparable specialized product portfolio.

Market position

Strengths4 records

Weaknesses4 records

Competitive moat4 records

Key risks5 records

Key highlights6 records

Customer concentration

Compliance1 record

Revenue estimate

Valuation estimate

Number of profiles

Profiles1 record

Funding overview

Funding rounds

Investors

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Diezinger