DIN 6797A External Tooth Lock Washers
M2 - M30
Spring steel zinc platedStainless steel
DIN 6797A covers external tooth lock washers — sprung teeth around the rim bite into the mating faces to resist loosening. We supply DIN 6797 washers across a range of metric sizes.
Also known as: external shakeproof washers, external star washers.
DIN 6797A dimensions
| Bolt Size | Inside Diameter | Outside Diameter | Tooth Height (min) | Thickness |
|---|---|---|---|---|
| M2 | 2.2mm | 4.5mm | 0.6mm | 0.3mm |
| M2.5 | 2.7mm | 5.5mm | 0.8mm | 0.4mm |
| M3 | 3.2mm | 6mm | 0.8mm | 0.4mm |
| M3.5 | 3.7mm | 7mm | 1mm | 0.5mm |
| M4 | 4.3mm | 8mm | 1mm | 0.5mm |
| M5 | 5.3mm | 10mm | 1.2mm | 0.6mm |
| M6 | 6.4mm | 11mm | 1.4mm | 0.7mm |
| M7 | 7.4mm | 12.5mm | 1.6mm | 0.8mm |
| M8 | 8.4mm | 15mm | 1.6mm | 0.8mm |
| M10 | 10.5mm | 18mm | 1.8mm | 0.9mm |
| M12 | 13mm | 20.5mm | 2mm | 1mm |
| M14 | 15mm | 24mm | 2mm | 1mm |
| M16 | 17mm | 26mm | 2.4mm | 1.2mm |
| M18 | 19mm | 30mm | 2.8mm | 1.4mm |
| M20 | 21mm | 33mm | 2.8mm | 1.4mm |
| M22 | 23mm | 36mm | 3mm | 1.5mm |
| M24 | 25mm | 38mm | 3mm | 1.5mm |
| M27 | 28mm | 44mm | 3.2mm | 1.6mm |
| M30 | 31mm | 48mm | 3.2mm | 1.6mm |
Materials & strength
External biting teeth
Teeth around the rim bite at the largest radius, maximising resistance to rotation.
Frequently asked
Internal or external tooth - which do I need?
External tooth washers grip over a larger radius and give the stronger locking bite; internal tooth washers hide the teeth under the fastener head. Match the pattern to the head size and the finish required.
Need DIN 6797A in a non-standard size or material?
Send us your drawing — specials quoted within 24 hours.