Manufacturer of non-metallic die-cut gaskets, from standard rings to custom shapes per customer drawing.

DIUNIS Wilhelm Gärtner GmbH Stanztechnik

WuppertalNew on Amplifa

1922Founded

5–1,500 mmRing sizes of the gasket rings

Up to millions of piecesSeries production possible

Since April 2024Part of the KLINGER Group

Competence through Tradition

DIUNIS Wilhelm Gärtner GmbH is a specialized manufacturer of non-metallic gaskets based in Wuppertal. Founded in 1922, the company has been producing die-cut gaskets for over 80 years, from standard rings to geometric shapes per customer drawings, including Hollander, raccord, flange, meter, valve, radiator and heating gaskets. Gasket rings are die-cut in ring sizes from 5 mm to 1,500 mm; production is carried out in rubber and asbestos-free fiber and high-pressure gasket materials from leading manufacturers such as Reinz, Klinger, Frenzelit and Hecker, complemented by in-house material developments such as DIUNIT 85 Gas. An in-house toolmaking operation with CNC-controlled machine tools ensures flexibility and precision; all lot sizes are possible, from single-part production to large-scale series in the millions of pieces. Customers are found in thermal engineering, gearbox manufacturing, gas and water supply, and other industrial applications. Since April 2024, DIUNIS has been part of the international KLINGER Group.

Site: Wuppertal
Processes: Die-cutting / stamping of gaskets (gasket rings, geometric shapes per customer drawing), Toolmaking (in-house toolmaking for stamping tools, ring sizes 5 mm to 1,500 mm), Manufacture of die-cut parts and high-pressure gaskets (certified scope), Application engineering consulting / material selection, SPC-supported quality monitoring (computer-assisted statistical process control with calibrated, Application engineering consulting, Toolmaking (in-house), Material selection
Materials: Rubber, Asbestos-free fiber materials, Asbestos-free high-pressure gasket materials (manufacturer Reinz), Asbestos-free high-pressure gasket materials (manufacturer Klinger), Asbestos-free high-pressure gasket materials (manufacturer Frenzelit), Asbestos-free high-pressure gasket materials (manufacturer Hecker), DIUNIT 85 Gas (in-house material development for service connections of gas pipelines), DIUNIT 85 Gas (in-house material)
Certificates: ISO 9001:2015, ISO 9001
Founded: 1922
Industries: Thermal engineering, Gearbox manufacturing, Gas/water supply, Industrial applications, Gas/water supply (meters, fittings)

01
Application engineering consulting and material selection
02
Toolmaking (in-house, CNC-controlled)
03
Die-cutting of gaskets
04
SPC-supported quality monitoring
05
Just-in-time delivery

Materials

DIU

DIUNIT 85 Gas (in-house material)

In-house material development for gaskets in the field of service connections of gas pipelines.

Rubber

Main material of the die-cut gaskets, with many years of processing experience.

AFW

Asbestos-free fiber materials

Processed for gaskets in industrial applications.

HDD

Asbestos-free high-pressure gasket materials (Reinz, Klinger, Frenzelit, Hecker)

Materials from leading manufacturers for the high-pressure gasket sector; recognized as a Reinz Premium Business Partner.

Location

Wuppertal

Headquarters / Production

Lot size: Single parts to large-scale series in the millions of pieces
Materials: Rubber, asbestos-free fiber materials, high-pressure gasket materials, DIUNIT 85 Gas

CNC-controlled machine tools
Specialized die-cutting machinery (largely in-house developments)
In-house toolmaking

Products

**Hollander and raccord gaskets**Die-cutting · Gas/water supply

**Flange and housing gaskets**Die-cutting · Thermal engineering / gearbox manufacturing

Inside the production

Industries

Thermal engineeringGearbox manufacturingGas/water supplyIndustrial applicationsGas/water supply (meters, fittings)

Processes & technical limits

Processes	Tolerance	Max. part	Weight	Lot size	Materials
Die-cutting / stamping of gaskets (gasket rings, geometric shapes per customer drawing)Forming	–	Gasket rings from 5 mm to 1,500 mm	–	Single-part production – Large-scale series in the millions of	Rubber, asbestos-free fiber materials, asbestos-free high-pressure gasket materials (Reinz,, DIUNIT 85 Gas (in-house material)
Toolmaking (in-house toolmaking for stamping tools, ring sizes 5 mm to 1,500 mm)Engineering	–	Ring sizes between 5 mm and 1,500 mm	–	–	Steel (tool steel, implied)
Manufacture of die-cut parts and high-pressure gaskets (certified scope)Forming	–	–	–	–	non-metallic materials
Application engineering consulting / material selectionEngineering	–	–	–	–	Rubber, asbestos-free fiber materials
SPC-supported quality monitoring (computer-assisted statistical process control with calibratedTesting	–	–	–	–	–

2 Anlagen & Maschinen

Machine	Manufacturer / model	Quantity	Working area	Year built	Site
CNC-controlled machine tools (stamping operation)	–	–	–	–	Wuppertal
Specialized die-cutting machinery (machinery park largely shaped by in-house developments)	–	–	–	–	Wuppertal

Additional services

Application engineering consultingToolmaking (in-house)Material selectionProcess managementJust-in-time deliverySample submission within 24 hoursSPC quality assurance

Reference customers

Reinz (Premium Business Partner award)

Quality

Ongoing quality assurance begins at order acceptance; machine and process capabilities are verified before production. Upon customer request, continuous monitoring is performed using computer-assisted SPC with calibrated and verified measuring instruments, supported by a quality management system according to DIN EN ISO 9001:2015.

Evidence	Wuppertal
ISO 9001

History

1922
Founded as a technical wholesale business
1977
DIUNIS emerged as a management buy-out by the Bauerfeld family
2024
In April, integration into the KLINGER Group