Durbal rod ends continue to impress with their unrivalled quality

Quality, reliability and precision

The history of Durbal Metallwarenfabrik GmbH dates back to 1938, when Wolfgang Schlegel, an amateur pilot, invented a spherical rod with a self-aligning bearing for aircraft steering. The company he founded in Berlin, Schlegel Luftfahrtgeräte KG, started out as a manufacturer of spherical joints for the aviation industry and later, as Durbal, introduced its developments to the automotive and other industries. Today, Durbal's heavy-duty rod ends have become an industry standard. 

During the difficult years of its history in the forties and fifties of the last century, despite numerous mergers and renames, the company passed all the tests with flying colours and, thanks to its determination and strategically correct policy, unique products and production activities, became known far beyond the borders of Germany. Its product range already included a wide range of mechanical metal components for numerous industries.

In 1959, the company adopted the more concise name of Schlegel KG and moved to the town of Oehringen in Baden-Wuerttemberg, Germany, an industrial region with a high concentration of engineering and metalworking companies. 

In 1979, the production of spherical plain bearings was separated from the production programme of Schlegel KG and the company with the present name Durbal GmbH was founded. The headquarters of Durbal GmbH, its entire team and production are still located in Oehringen, Germany. 

Durbal has been manufacturing rod ends for eight decades. The rod ends with integrated self-aligning ball bearings were originally used in the aerospace industry under the brand name Schlegel, after the company's founder. Today, Durbal's heavy-duty rod ends are recognised for their quality, reliability and precision by professionals in all sectors of industry.

Much of the machining of forged parts for the production of ready-to-install precision products in the Durbal Premium Line, and a large part of the Durbal Classic Line, is carried out using specialist machines and tools designed and built specifically for the manufacturing processes. The turning, milling and cutting of carbide parts is also carried out using the latest technology, developed to meet the exact requirements of the company's production systems, to ensure products of unrivalled quality, maximum precision and cost effectiveness.

The assembly of high quality products, such as self-aligning roller bearings in rod ends and Durbal premium spherical plain bearings for heavy duty applications, is carried out manually at the company's production site in ergonomically designed workstations specially adapted for this process. 

As a customer-focused company, Durbal is constantly expanding its product range. The company is also able to respond to individual customer requests for technical modifications to the rotation, tilt and swivel of the company's system components. This capability is the company's 'Foresight Technology' concept, which has proved its worth over the years. Durbal's dynamic development is not only a reflection of family tradition, but also of environmental awareness, as evidenced by the company's ISO 1400:2015 certified production.

The company's product quality management is certified according to ISO 9001:2015 and the new European standard EN 9100:2018 in the aerospace and defence sector. All Durbal products are manufactured using state-of-the-art production processes and product quality control is carried out at each stage of the manufacturing process as well as upon release of the final product. The environmental friendliness of Durbal's products and production processes is not only the company's tradition, but also the concern of all employees for the environment, as evidenced by the ISO 14001:2015 standard. 

More than 500,000 finished products are produced annually in the company's production facilities, meeting the needs of industry in Germany and Europe, and exported to more than 60 countries worldwide. All Durbal products stand out from their closest competitors due to their excellent price/performance ratio, ensuring that the company's customers can always find the right and most efficient solution under the Durbal brand.

In 2014, Durbal was acquired by the renowned Italian company Nadella Group and has successfully added its high quality products to the company's wide range of products.

In 2023, Nadella was acquired by Rollon (by Timken) and today Durbal is the Timken Group's expert in the design and manufacture of rod ends, spherical plain bearings and rod systems. The companies now serve global industries such as machinery and packaging with a diversified product portfolio. 

The combined product portfolio and market presence of global leader Timken and the Rollon, Nadella and Durbal companies is unrivalled today. The companies are part of the global sales and distribution network of a giant like Timken and have access to customers in every corner of the world.

The Durbal product range

The Durbal product range consists of 3 main product groups: 

• Premium Line - the highest quality for applications where no compromises can be made, 

• Classic Line - the most popular range with an optimum price/performance ratio and 

• Basic Line - the budget range

The product range is completed by customised rod systems with various components based on spherical plain bearings, rod ends, forks and angle joints as well as accessories.

The Durbal catalogue contains approximately 2,700 product designations and sizes standardised in accordance with DIN ISO 12240-1, as well as numerous industry-specific solutions, which cover a wide range of requirements for industrial machines and systems and have made the company a reliable partner for many companies in different industries for many years. These products are used successfully in almost all industries, with individual products being used with great success in the aerospace, automotive and railway industries.

The product range extends from rolling bearings, spherical plain bearings, maintenance-free and low-maintenance rod ends and heavy-duty rod ends to products in stainless steel and aluminium. High axial or radial loads, difficult operating conditions or special coatings for aggressive environments are covered by the Premium Line and Classic Line. These products are particularly appreciated by manufacturers of industrial equipment. In addition, Durbal produces limited editions of special heavy-duty rod end systems, characterised by high precision and reliability.

Durbal Premium Line

One of the latest additions to Durbal GmbH's product range is the Premium Line of heavy-duty rod ends with integrated bearings, consisting of standard and special products as well as customised series. This heavy-duty product line features rod end variants with integrated self-aligning roller bearings and ball bearings.

The DURBAL Premium Line is designed for particularly heavy-duty applications and includes BRTM and BRTF heavy-duty rod ends with integrated self-aligning roller bearings.

Rod ends BRTM and BRTF with integral self-aligning roller bearings are mainly used for high speeds, large swivel angles or swivels with higher loads. Rod ends of this design have a much higher rated load capacity. 

These rod ends are factory filled with high quality long life grease and are maintenance free under normal operating conditions. The grease can be changed as required via a grease nipple in the housing. To avoid incompatibility with the original factory lubricant, the use of greases based on an aluminium soap complex is recommended. Protective metal washers on both sides of the bearing prevent larger dirt particles from entering the bearing and keep the grease safely inside the bearing. 

Rod ends with integral bearings are specially heat treated to achieve increased raceway and sliding hardness, which reduces bearing friction and ensures high dimensional stability under varying loads. 

The premium range also includes BRM, BRF, PM and PF rod ends with integral ball bearings for heavy duty applications.

BRM, BRF, PM and PF rod end with integral self-aligning ball bearings are particularly suitable for high speeds, large swivel angles or rotary motion with relatively low to medium loads. Excellent technical features such as low bearing friction, high quality long life lubrication and protective washers and seals on both sides reliably prevent large dirt particles from entering the bearing.

These rod ends are factory filled with high quality long life grease and are maintenance free under normal operating conditions. If necessary, the grease in these products can be changed using a grease nipple fitted to the housing. To avoid incompatibility with the original factory lubricant, we recommend the use of aluminium soap complex based greases. 

These rod ends are also specially heat treated to achieve increased raceway and sliding hardness, which reduces bearing friction and ensures high dimensional stability under varying loads. 

Durbal GmbH carries out a 100% radial clearance check on every spherical plain bearing in the Premium product line and also offers this product line in a stainless steel version with DIN ISO 12240-4 and DIN ISO 8139 internal or external threads on the shaft or inch dimension.

Durbal Classic Line

This product range includes high performance rod ends of types BEM, BEF, EM and EF with integral maintenance free and maintenance required spherical plain bearings. 

These products in the Classic Line are designed for small swivel angles or tilting movements at low speeds. They offer high load capacity and impact resistance. The rod ends in this range use backlash-free Durbal sliding technology and have a bearing clearance of just 0-10 microns with a light preload in the ball joint. The hard chrome plated ball of these rod ends is embedded in a special Durbal-Glide® insert made from glass fibre reinforced PTFE polymer. The bearing design is maintenance free and provides a completely backlash free bearing. The polymer used in the bearing has beneficial properties and is capable of absorbing any foreign particles, accumulating them in certain quantities and thus eliminating them from the friction process.

The Classic Line also includes heavy-duty rod ends of types BEMN, BEFN, EMN and EFN with integral maintenance-free spherical plain bearings. These rod end types with maintenance-free or maintenance-required spherical plain bearings are primarily designed for alternating and shock loads or large rotary movements. They also have an integral chrome plated spherical plain bearing (types BEFN and BEMN) with effective corrosion protection to prevent rusting of the bearing surfaces even in humid conditions. 

All spherical plain bearings in this range have forged and hardened housings and are extremely wear resistant, while the plain bearings are made from hardened roller bearing steel, ground and polished on all sides and chrome plated on the raceways. 

The shaft is available with internal or external threads to DIN ISO 12240-4 and DIN ISO 8139 in metric or imperial sizes. 

All of the high strength Durbal rod ends in this range have no critical fracture points on the outer ring for increased strength. These compact, high strength rod ends are ideal for extremely high loads and are even suitable for shock loads.

Durbal rod ends with high strength anodised aluminium housings

The Durbal Classic Line includes K and E series rod ends with high strength aluminium housings and integrated maintenance-free bearings. Due to their low weight, corrosion resistance and high mechanical strength, these products have proven themselves in industrial products in general engineering. Key features and benefits of aluminium rod ends:

• Extremely light weight compared to steel rod ends; for example, a size 12 ALU product weighs only 0.057 kg, while a stainless steel product weighs 0.109 kg

• The Durbal-Glide polymer insert of the maintenance-free plain bearing is made of glass-fibre reinforced PTFE polymer and is able to absorb foreign particles entering the bearing

• The bearing balls are made of hardened roller bearing steel or stainless steel, the sliding surface is ground, polished on all sides and chrome-plated

• The housings are made of high-strength, corrosion-resistant aluminium with an extremely hard, scratch-resistant surface, which can be anodised in various colours

• In addition, all aluminium rod end housings have a high mechanical strength and are generally designed for the same nominal loads as steel products, e.g. the steel rod end size 12 can withstand a static load of 23 kN and the aluminium rod end Durbal BEFA 12-60-501 can withstand a static load of 22.1 kN, which is significantly higher than the stainless steel version of the rod end size 12, which can withstand a static load of 15 kN

• Backlash-free bearing design with radial clearance of 0 - 10 microns

• The aluminium rod ends can be successfully used for impact loads and are designed for small swivel movements at low speeds

Durbal Basic Line

This traditionally high-quality product line comprises a wide range of rod ends and spherical plain bearings in various designs, rod ends for hydraulic cylinders and accessories. All rod ends and spherical plain bearings as well as rod ends for hydraulic cylinders are ready-to-install standard components for machines and systems that transmit static and dynamic forces from rotating, tilting and swivelling movements. 

The extensive product programme includes the following combinations of sliding surfaces with conventional functions:

• Steel on steel

• Steel on bearing brass

• Steel on brass with PTFE composite

All components of Durbal products are subjected to a strict incoming goods inspection, which is based on random sample tests in accordance with the procedure of the German Quality Association. If a random sample fails, the entire batch is rejected. Conformity of the design with the drawings is of the utmost importance. 

Agreements based on mutual concessions in the event of deviations are not part of company policy and will not be granted. In addition, all Basic Line products are laser marked by Durbal at the factory after completion to ensure the highest product quality and traceability throughout the product supply chain. 

As a certified company, Durbal GmbH audits its suppliers annually in accordance with the requirements of international ISO standards. The company pays particular attention to a long-term environmental protection programme.

The most important features of the rod ends and spherical plain bearings of the Durbal Basic Line are:

• High bore accuracy

• High thread accuracy

• Correct positioning of the PTFE insert in the spherical plain bearings is essential for all spherical plain bearings

The standard products of the Durbal Basic Line are characterised by high precision and reliability as well as an attractive price/performance ratio.

Hydraulic heavy-duty rod ends are a part of the Durbal Basic Line. These rod end types with pressed-in spherical plain bearings and female threads have been developed in accordance with ISO 6982 and DIN 24338 for hydraulic cylinder applications. 

The maintenance-free rod ends for hydraulic cylinders absorb radial forces in tension or compression and can transmit movements and forces with low torques. They are particularly suitable for alternating radial loads and unilateral loads. The thin-walled design of the shaft body allows compact connection designs.

The threaded part of the shaft is equipped with a threaded clamping device consisting of a slot and two hexagon socket head cap screws to DIN EN ISO 4762. 

Design features:

• Special design with slotted shaft body and clamping screws,

• Female thread right or left,

• Suitable for high static, alternating or shock loads.

The housings are made of forged and hardened steel. The bearing outer rings are made of hardened roller bearing steel, ground and phosphated, with groove and lubrication holes. The inner rings of the bearing are made of hardened roller bearing steel, ground and phosphated. 

The Durbal hydraulic rod ends are available in high-strength, weldable steel with rectangular or round welding surfaces and are used for mounting on the bases of hydraulic cylinders. The rod ends comply with DIN ISO 12240-4 and are equipped with a round welding surface, a locking pin at the base of the shank and a welding bevel. 

In addition to the standard versions, Durbal GmbH supplies other special versions of these products in consultation with the customer:

• Hydraulic rod ends requiring maintenance,

• With other types of grease nipples or with a threaded connection for central lubrication,

• Rod ends for hydraulic cylinders with maintenance-free spherical bearings,

• Rod ends with special shaft threads,

• Rod ends with different corrosion protection

Large Radial Spherical Plain Bearings for Heavy Duty Applications

As part of the Basic Line, Durbal GmbH manufactures large spherical plain bearings with shaft bore diameters from 100 to 1000 mm. These bearings are available in maintenance-free or maintenance-required versions and can be manufactured from stainless steel or other materials on request. 

Durbal Large Spherical Plain Bearings used in heavy industry can have a significant impact on overall equipment performance and total cost of ownership. Bearings rarely operate in ideal conditions. In heavy industries such as mining and ore processing, large spherical plain bearings are used in many types of equipment. However, the operating conditions in these industries are very harsh, which can significantly shorten the life of the bearings and the entire system. 

Durbal GmbH has responded to the needs of its customers in heavy industry and has not only extended its range of spherical plain bearings by increasing the bore diameter to 1000 mm, but has also included spherical plain bearings for many of the bearing series commonly used in these industries in its standard range. With a wide range of spherical plain bearings, Durbal GmbH can offer the advantages of its solutions, which include lower total cost of ownership and longer maintenance intervals. In addition to the mining and mineral processing industries, Durbal's large spherical plain bearings can be used in the following applications:

• Overflow ladles in steel works

• Hydroelectric power stations and dams

• Offshore ship docks

• Offshore and onshore structures, cranes

• Pivoting or suspended bridge structures

• Sliding roofs for large buildings and stadiums

• Parks and leisure facilities

Durbal develops and produces a variety of tailor-made solutions for customers who require a complete mast system for heavy loads. These systems are part of the Durbal Premium Line, although any product from the company's Premium, Classic and Basic product lines can be installed. 

Durbal's product range includes a variety of solutions to cover all customer needs. Durbal's tie rod systems for the transmission of dynamic and static forces are available with both internal and external threads. The various components of these high-strength systems are manufactured with the highest quality, precision and reliability. 

The company offers these systems in different material variants such as steel, stainless steel, aluminium and others on request. These variants can include the following types of tie rod systems:

• Hexagonal and flat bars, flat bars or tubular tie rods

• Tie rods in different sizes

• Tie rods with internal or external threads

• Tie rods with pressed spherical bearings

• Tie rods with integrated Durbal bearings

The specialists at Durbal GmbH are ready to adapt these systems to the specific requirements of each application. Customers are offered a wide range of combinations from the entire product range: all series of high performance rod ends and spherical plain bearings, forks and angle joints. 

Main features and advantages of the rod end systems:

• Numerous product combinations are available, which can be combined individually or in modular form

• These easy-to-use system solutions significantly reduce assembly and set-up times for machines and systems

• Simple assembly of machines and systems by reducing the number of products (one system instead of various individual components) 

The surfaces of the system components can be provided with various coatings by means of chromium-free galvanising, painting and special coatings, chrome-plating or anodising (other coatings on request).

Accessories for Durbal rod ends

Durbal GmbH manufactures and distributes an extensive range of accessories for rod ends with possible combinations of products from the Durbal Premium Line, Durbal Classic Line and Durbal Basic Line.

The available range of accessories includes the following products:

Special coating Durbal-Coat®

The maintenance-free rod ends of the Durbal Classic Line can be supplied with a special Durbal-Coat® coating. This multi-stage process produces a surface coating with very good anti-corrosion properties, as proven in numerous salt spray tests. The coating structure consists of a zinc-nickel layer produced by cathodic electrodeposition, followed by passivation and a final coating with an organic enamel containing aluminium flakes. 

With this method of galvanic zinc-nickel coating, Durbal GmbH has achieved a successful combination of highly effective corrosion protection with an attractive surface appearance. Typical applications for zinc-nickel coated products include the automotive industry, the electrical industry, industrial machinery and general mechanical engineering as well as metalworking. In addition, many materials that are very difficult to coat, such as cast iron, can be safely and reliably coated using this process. 

Following the publication of the new European Directive, many manufacturers have been forced to change their surface coating technology for chrome-free coatings on metal products. Durbal GmbH supplies its products with a high-quality galvanic zinc-nickel surface coating without chromium compounds, which meets all requirements and regulations of the automotive industry and even exceeds many regulations. This specially developed corrosion protection system is heat-resistant and retains its protective effect even under extreme temperature conditions, e.g. in the engine compartment of the vehicle or in the brake area. This corrosion protection coating is environmentally friendly and has already proven itself in practice.

It is suitable for steel and cast iron. The corrosion resistance parameters obtained in tests of the products in independent test laboratories have shown that the coated products can be used in a humid environment for up to 720 hours without red rust, which corresponds to DIN EN ISO 9227. 

Customers of Durbal GmbH will also appreciate the fact that the classic range of heavy duty rod ends, which are treated with special Durbal coatings, have a higher load capacity than the stainless steel versions of the same range. These products are also a more economical solution than the stainless steel versions.

Special products according to customer specifications

Durbal develops and manufactures customised products from the extensive product range of the Durbal Premium Line, Classic Line and Basic Line. 

This process starts with the customer providing individual specifications and drawings, which are checked and implemented by Durbal's technical staff or, if necessary, design changes are made to Durbal's standard products in consultation with the customer. In this way, Durbal GmbH ensures that customers receive the best possible solution for their requirements. 

With its special rod ends and spherical plain bearings, Durbal makes a special contribution to customer requirements. Durbal GmbH makes a special and valuable contribution to the new technical developments of industrial machine manufacturers. Durbal's spherical plain bearings and rod ends for heavy-duty applications, which are designed to meet special clearance and friction torque requirements, can also make a significant contribution to the success of machine manufacturers.

CMT GmbH is a long-standing premium partner of Durbal

CMT GmbH stocks a wide range of Durbal products. When you work with us, you can rely on the best prices, the shortest delivery times and the advice of our specialists, who are always on hand to help you with selection and processing.