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Washer Selection — ISO 7089 / 7090
Look up flat and spring washer dimensions per ISO 7089/7090 and DIN 127. Select bolt size to view washer ID, OD, and thickness.
Results
Flat Washers — ISO 7089 (Normal Series)
| Bolt | ID (mm) | OD (mm) | t (mm) |
|---|---|---|---|
| M6 | 6.4 | 12 | 1.6 |
| M8 | 8.4 | 16 | 1.6 |
| M10 | 10.5 | 20 | 2.0 |
| M12 | 13.0 | 24 | 2.5 |
| M16 | 17.0 | 30 | 3.0 |
| M20 | 21.0 | 37 | 3.0 |
| M24 | 25.0 | 44 | 4.0 |
ISO 7089 = plain flat washer. ISO 7090 = same dimensions but with a chamfer (beveled edge) on one side to prevent digging into soft surfaces.
ISO 7089: ID 10.5 mm, OD 20 mm, thickness 2.0 mm.
Spring washers (DIN 127) were historically used for vibration resistance. Modern practice prefers Nord-Lock, Belleville washers, or threadlockers.
ISO 7089: 200 HV minimum. For class 10.9/12.9 bolts, use 300 HV washers to prevent embedding.
Recommended when: oversized holes, soft/painted surfaces, high-strength bolts, uneven surfaces, or slotted holes.
The procedures described on this page were developed and field-tested by the Vibromera team using the Balanset-1A, a portable dual-channel balancer and vibration analyzer for on-site rotor balancing.
Nikolai Shelkovenko
Nikolai Shelkovenko is a vibration analysis engineer and the founder and CEO of Vibromera. For more than 15 years he has balanced rotating equipment in the field rather than on a test bench: mulchers, industrial fans, crushers, centrifuges, shafts and spindles. That work is what the Balanset instruments grew out of — they were designed as a tool a specialist can carry to the machine and use alone, on site, not as laboratory equipment. Vibromera was founded in 2017 and has been based in Porto, Portugal, since 2023. Development, assembly and support of the Balanset line all happen here. The flagship instrument is the Balanset-1A, a portable analyser for single- and two-plane balancing and for vibration diagnostics. Nikolai is personally involved in customer support, in working through difficult balancing cases and in the development of the software. He works with customers worldwide, in any language.
