Metric PPM washers

Metric metal-rubber washers

Metal-rubber washers metric PPM ( for metric threads )

What are metric PPM washers? 

Metric PPM washers are sealing elements made from a combination of metal and rubber, which are used in various hydraulic and pneumatic systems. Thanks to precise workmanship and the use of durable materials, these washers ensure effective sealing and resistance to high pressures and temperatures. Metal-rubber washers are intended for sealing threaded connections. The washers are used in the place where the threaded connection is sealed. Metal-rubber washers have replaced the copper washers used in the past. For each washer, it is specified which thread it is intended for. For example, an M10 washer is suitable for sealing M10x1 or M10x1.5 threads. Execution: steel + NBR rubber. The washers are self-centering - the rubber surface adheres tightly to the thread and seals it.   Some straight fittings are originally equipped with ED seals (rubber seals); in such cases, we do not need to use additional washers.

When should a metal-rubber washer be used? 

Washers are used with fittings with a larger hexagon that do not have any sealing - to ensure the connection is leak-proof, they require the use of a metal-rubber washer. Such a washer is placed on the thread and pushed up to the hexagon. Some fittings have a special recess specifically for the use of metal-rubber washers. 

Available PPM washer sizes

The category offer includes washers in standard metric sizes, such as: M6, M8, M10, M12, M14, M16, M18, M20, M22, M24, M26, M30, M33.

In which industries are metal-rubber washers used

Application of metric PPM washers. PPM washers are widely used in many industries, such as: Hydraulic industry: Sealing threaded connections in high-pressure systems. Automotive industry: Seals in fuel, cooling, and oil systems. Machinery industry: Applications in industrial machinery, such as hydraulic presses or construction machinery. Pneumatic industry: Seals in air and gas installations.

Other types of self-centering washers 

In addition to metric PPM washers, we also offer:

• PPG imperial washers: Designed for imperial sized threads, ideal for systems that require specific connection standards.
• Metal-rubber washer kits: Sets of washers in various sizes, which are a practical solution for users requiring flexibility and versatility in applications.

Washers with a rubber seal – what is it?

The term "washers with a rubber seal" is a common name for metal-rubber washers (bonded seals), which combine the strength of metal with the flexibility and tightness of an elastomer. The construction of such a washer consists of a steel ring (most often made of galvanized or stainless steel) and a permanently vulcanized rubber seal. Thanks to this solution, washers with a rubber seal fulfill two functions simultaneously: mechanical – the metal provides appropriate strength and stability of the bolted connection, sealing – the rubber adapts to the surface, eliminating the risk of leaks even at high pressure.

Metal-rubber washers application

Washers of this type are widely used in power hydraulics, pneumatics, fuel and oil installations, as well as in water and heating systems. They ensure tightness, reduce the risk of damage to the sealed surfaces, and prove useful where ordinary metal washers do not guarantee adequate sealing. Why is it worth choosing them? Metal-rubber washers, also known as washers with a rubber seal, are characterized by high durability, ease of installation, and universal application. Depending on needs, they can be selected with different types of elastomer, such as NBR, EPDM or Viton (FKM/FPM), which allows the product to be matched to specific working conditions.  Metric PPM metal-rubber washers are used in a very wide range of installations. They are used in bolted connections, hydraulic plugs, straight and elbow fittings, as well as in hydraulic blocks and manifolds. They are perfect for construction, agricultural, and industrial machinery, as well as in mobile hydraulic systems. Thanks to their resistance to hydraulic oils, greases, and fuels, they can also be used in service and repair installations.

Metric washers for metric threads

PPM metric sealing washers are designed for use with metric threads commonly used in European power hydraulic systems. Proper selection of the internal and external diameter of the washer has a direct impact on the tightness of the connection. Hydron's offer includes variants adapted to popular thread sizes, which facilitates the quick selection of the right element both in new installations and during service work.

Metric PPM sealing washers

Metric PPM sealing washers are a proven solution used in power hydraulics, pneumatics, and industrial installations where tightness, durability, and safety of threaded connections count. The metal-rubber construction combines the mechanical resistance of the steel ring with the flexibility of the rubber insert, which allows for effective sealing even under varying operating conditions and high pressures. Hydron offers PPM washers in a wide range of metric sizes, adapted to the most common threads used in power hydraulics.

Why are washers so popular in power hydraulics? 

The popularity of PPM metal-rubber washers stems from their universality and reliability. Installation is quick and simple, without the need for additional seals. The connection can be repeatedly disassembled and assembled if necessary, maintaining high tightness, as long as the washer is not mechanically damaged. This is a solution valued by service technicians, fitters, and machine users who expect durability and predictable operation of the hydraulic system.