Dubo® retaining washers

ORIGINAL Dubo® design to effectively secure connections

Dubo® retaining washers are effective and easy to use. Dubo® retaining washers have a unique design which forces the nylon to encase the screw thread and the bolt hole when the connection is tightened. It offers an effective and cost-effective solution for manufacturers and installers who need permanent, durable locking.

Excellent locking, sealing, and material protection properties

Dubo® retaining washers create an exceptionally high coefficient of friction at the bolt and the bolt hole which prevents unscrewing, loosening, and leaks. These retaining washers also absorb vibrations, which helps dampen any noise and prevents bolts suffering wear and metal fatigue. The material is resistant to external influences from various types of fluid and has an isolating effect, preventing galvanic corrosion between different materials.

For threaded fasteners from M2 – M52

Dubo® retaining washers are made of a super polyamide; elastic and extremely strong nylon 6. It can be used both standalone and in combination with a steel Dubo® toothed collar washers. These are required in heavy-duty applications, such as when using 8.8 and 10.9 bolts. Nylon retaining washers are available for threaded fasteners from M2 to M52.

Advantages of Dubo® retaining washers

These retaining washers are genuine Dubo® Originals, which we invented in 1951 and have been crafting and perfecting ever since. Their quality is undisputed, and they offer a number of extremely important advantages:

Dubo - retaining washers
Part.No.Ref No.MetricInch
1002000000000197M2 5,302,101,500,50500


A Dubo® retaining washer forces itself into the screw thread, the bolt hole, and around the nut, creating an exceptionally high coefficient of friction between itself and the bolt. As a result:
  • the retaining washer is unable to rotate around the bolt;
  • the nut cannot loosen;
  • and a liquid-tight connection is created.
Dubo® retaining washers:
  • absorb vibrations in the bolt connection;
  • have a plastic-elastic effect;
  • and so far as we know are free of substances listed by the European Chemicals Agency (ECHA) as an SVHC.
Dubo® retaining washers:
  • are resistant to alkaline liquids, solutions of inorganic neutral salts, oils, greases, and common chemicals such as petrol, alcohol, diluted acids, and sea water;
  • prevent galvanic corrosion between connected parts;
  • and prevent metal fatigue of the bolt.
  • Aerospace
  • Railway
  • Electronics
  • Assembly
  • Construction
  • Maintenance
  • Elastic limit: 7 N/mm2
  • Ultimate tensile strength: 26 N/mm2
  • Elastic Modulus: 6,600 kg/cm2
  • Dielectric strength: 18 kV/mm
  • Hardness in degrees
  • Rockwell: HRC 115
  • Specific weight: 1.14

Assembly instructions for Dubo® retaining washers

To ensure bolts are locked and sealed reliably, observe the following assembly instructions:
  1. The bolt should be tightened until the outer reinforcing rim of the washer is deformed and tightened around the screw head. This indicates the bolt has been sufficiently tensioned. Because the retaining washer is squeezed around the bolt, it may appear that the bolt needs to be tightened further, but this is not the case. As soon as the retaining washer deforms, it means the tension is sufficient and the bolt is fully tightened. Further tightening is damaging and not recommended.
  2. The smoothest finish possible on the contact surface of the component improves the locking and sealing.
  3. Choose the right size retaining washer for each bolt hole.
  4. For perfect sealing, the specifications for bolt holes in accordance with DIN 69 medium or fine must be observed.
  5. If the Dubo® lock washer is used with a Dubo® toothed collar washer, the bolt can be tightened to any permitted torque value.

Can be used in combination with:

Dubo - Toothed collar washers

Dubo® toothed collar washers

The Dubo® toothed collar washers reinforces the properties of a Dubo® retaining washer. As a true Dubo® Original, it guarantees excellent quality. The collared tooth lock washer is made of steel or stainless steel and designed for use with high-quality 8.8 and 10.9 steel bolts.

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More info?

If you have any questions about the original Dubo® or KORREX® products, check out the FAQs on our site or contact us. We’ll be happy to hear from you!

Disclaimer: All descriptions, technical information, drawings and dimensions on this website have been compiled by Dubo Dorned B.V. with the greatest care. Nevertheless, Dubo Dorned B.V. cannot accept any liability for type-setting and typographical errors, technical changes to the products or for any incidental or consequential damage in connection with our technical statements or our ability to deliver. All drawings and descriptions on this website are in no way of an agreed quality. The information herein concerns typical values intended for reference and comparison purposes only. It should NOT be used as a basis for design specifications or quality control. Contact us for full material property datasheets from manufacturers. Understandably, the application of the products listed assumes expertise on their use and assembly as well as standards. All our offers and any subsequent orders and agreements resulting thereof are exclusively subject to the General Terms and Conditions of Dubo Dorned BV.