Description

Rubber Bellows: Cylindrical, Rectangular and Cone

Barbieri Rubber has been manufacturing rubber bellows since 1963 — cylindrical, rectangular, conical and modular — for protection of shafts, spindles, rods and moving parts in industrial environments. As a rubber bellows manufacturer based in Reggio Emilia, Italy, we produce standard catalog items and custom rubber bellows made to customer drawing, in NBR, EPDM, silicone (VMQ), neoprene and other technical compounds. All molding is carried out in-house in our plant in Emilia-Romagna.

Rubber bellows types

The rubber bellows range includes four main product families. Cylindrical rubber bellows protect circular-section components — spindles, rods, rotating shafts, hydraulic cylinders — with a corrugated profile that compresses and extends to follow the stroke. Modular bellows are assembled from single elements to cover variable lengths and irregular geometries: the standard solution for telescopic guides and custom strokes. Rectangular rubber bellows cover square and rectangular guides on machine tools and industrial equipment. Conical rubber bellows connect sections of different diameter and follow angular deflections, used in linkages, joints and articulated mechanisms.

Rubber bellows for shaft and spindle protection

Rubber protective bellows are the standard solution for shaft and spindle protection in machine tools, CNC machining centres, hydraulic and pneumatic cylinders, and industrial automation equipment. The key function is threefold: retaining lubricant near moving parts, preventing swarf, metal dust, coolant and aggressive fluids from entering the protected zone, and absorbing minor misalignments and oscillations. For applications with heavy metal dust — milling, grinding, turning — we select abrasion-resistant compounds and geometries optimised for swarf evacuation. Joystick rubber boots are a dedicated product within this family, produced for control levers in agricultural machinery, construction equipment and industrial vehicles.

Available compounds

NBR bellows are the industrial standard for contact with mineral oils: used in hydraulic systems, oil-hydraulic components, automotive and heavy machinery. EPDM rubber bellows resist water, steam, ozone and UV — the choice for outdoor installations, photovoltaic systems and water-hydraulic circuits. Silicone (VMQ) bellows cover the widest operating temperature range (-60/+200 °C), suited to food industry, medical applications and high-temperature environments. FKM (Viton®) is available for chemically aggressive conditions — aggressive oils, solvents, fuels. Neoprene provides a good general-purpose balance between chemical and mechanical resistance. Compound and hardness are selected based on operating environment, stroke, frequency and service life requirements.

Compound	Temperature range	Chemical resistance	Typical applications
NBR (Nitrile)	-40 / +130 °C	Mineral oils, fuels	Hydraulics, automotive
EPDM	-40 / +100 °C	Water, steam, ozone, UV	Hydraulics, outdoor, photovoltaic
VMQ (Silicone)	-60 / +200 °C	High temperature, biocompatible	Food, medical, high-T
FKM (Viton®)	-10 / +180 °C	Aggressive oils, solvents, fuels	Chemical, automotive, hydraulics
HNBR	-20 / +160 °C	Oil + high temperature	Heavy-duty hydraulics
NR / SBR	-50 / +90 °C	Good mechanical elasticity	Anti-vibration, general

Standard and made-to-drawing bellows

The standard catalog covers the most requested diameters, heights and compounds, with active molds and no tooling cost for the customer. For specific geometries — non-standard diameters, variable cross-sections, rubber-to-metal bonded inserts, custom flanges — we produce custom rubber bellows and industrial rubber bellows starting from the customer’s drawing, even at a preliminary stage. A draft drawing with the main dimensions and operating conditions is the minimum requirement for any custom production. Mold manufacturing is carried out with qualified toolmaking partners; all molding is in-house. Minimum quantities and lead times are agreed based on mold complexity and compound selection.

FAQs

What are rubber bellows?

Rubber bellows are molded elastic parts with a corrugated accordion profile, manufactured to protect shafts, spindles, rods and moving parts from dust, swarf, dirt, coolant and lubricant loss. The corrugated geometry allows the bellow to compress and extend — following the stroke of the protected component — while maintaining a continuous protective seal around the moving part.

Which rubber bellows types does Barbieri Rubber produce?

We produce four main types: cylindrical (circular cross-section, for spindles and rods), modular (assembled from single elements for variable strokes), rectangular (square or rectangular cross-section, for linear guides on machine tools) and conical (connecting sections of different diameter). We also manufacture joystick rubber boots for control levers and rubber bellows for elastic joints with specific mating dimensions.

Which compound should I choose for bellows?

NBR is the standard for mineral oils in hydraulics and automotive applications. EPDM suits water, steam, ozone and UV — ideal for outdoor and hydraulic systems. Silicone (VMQ) covers the widest temperature range (-60/+200 °C) and food or medical requirements. FKM (Viton®) resists aggressive oils, solvents and fuels. Neoprene is a general-purpose alternative. The compound is selected based on the fluids present, operating temperature, and mechanical demands of the application.

Can I order custom rubber bellows?

Yes. We produce custom rubber bellows and industrial rubber bellows from any drawing supplied by the customer, even at a preliminary stage — with at least the main dimensions (extended length, compressed length, inner bore, outer diameter, wall thickness) and the operating conditions. The dedicated mold is built with our toolmaking partners; molding is fully in-house. We handle the entire production cycle from compound selection to finished part.

Are Barbieri Rubber bellows suitable for CNC machine tools?

Yes. Rubber bellows for spindle and axis protection are among our core products for the machine tool sector. For CNC machining centres, milling and grinding machines, we produce rubber protective bellows in abrasion-resistant compounds, dimensioned for the specific stroke and guide geometry. We also produce rubber bellows for hydraulic and pneumatic cylinders used in CNC equipment.

Additional information

Rubber bellows features – pick up here	The rubber bellow protects the internal device from dust, dirt, UV rays, sand, wood or metal chips, humidity, water sprays (or liquids in general), oils, chemicals, and other contaminants. The rubber material remains flexible during its lifespan even in harsh environmental conditions and applications. In more than 50 years of continuous research and development of compound formulations and accelerated life tests, Barbieri Rubber has produced unique compounds with high elasticity properties and excellent durability. These characteristics have opened up new applications, which wouldn't have been possible with previous compounds. In 2010, Barbieri supplied protection bellows to the Archimede solar power plant and many other power plants and solar farms around the world, such as in Sweden and in the Sahara Desert, where extreme temperatures and the presence of abrasive contaminants make installations particularly challenging.
Special rubber compounds for boots and bellows	The development of rubber materials resistant to oil, grease, fat solvents (and even some acid ones) has allowed us to use bellows to protect devices in environments strongly contaminated by lubricants and solvents: Hydraulic remote controls and distributors, hydraulic valves and brake clamps, brake pumps, hydraulic systems in general, and hydraulic cylinders. Other applications include sensors and electronic controls, as well as pneumatic and cable remote controls which are used in less harsh conditions where only long life and sturdy mechanical features are required.
Bellows protection: Restrictions and Relative Solutions	Protection Device Only Bellows can be used only as protection devices. They do not withstand radial and axial mechanical stress or difference in internal and external pressure. Therefore, they are not suitable for conveying fluids or protecting against crushing. Solution: Use metal bellows (used for joining pipes), which can be adapted to any dimension. Should the dimensions of the modular bellow be out of range, you can use standard bellows or custom bellows, which will solve the problem once and for all.
Availability	Since bellows are not regulated, it is extremely difficult to find them on the market with dimensions suitable for certain specific applications. Usually, designers tend to neglect this problem. In many cases, the market cannot provide a product with the desired dimensions, so that the purchaser will often opt for the one that best suits the dimensions of their machinery. The result is that machinery comes with unacceptable solutions. Solution: Use the modular bellow (prompt delivery), which can be adapted to any dimension. Should the dimensions of the modular bellow be out of range, you can use standard bellows or custom bellows, which will solve the problem once and for all.
Materials	The material does not affect the stroke and dimensions of the bellow. Therefore, the material must be chosen depending on the environment where it is used, this will ensure a long-lasting and efficient protection device.

Rubber Bellows