# Serrated (tooth) lock washers, DIN 6798 forms A, J, V: M1.6–M30 bore, outside diameter, thickness, number of teeth

> What are the dimensions of a DIN 6798 serrated lock washer, and how many teeth does an M6 external tooth washer have?

- Category: Hardware › Fasteners
- Kind: Standard part
- Basis: Engineers Edge's DIN 6798 table (forms A, J, V), GlobalFastener's form A table (M1.6 to M30) and McMaster-Carr's DIN 6798 listings (18-8 external tooth and zinc steel, plus countersunk); numbers only
- Page: https://xemstudio.com/objects/serrated-lock-washers-din-6798/ · JSON: https://xemstudio.com/api/geometry?object=serrated-lock-washers-din-6798 · Plain text: https://xemstudio.com/objects/serrated-lock-washers-din-6798/sheet.txt
- License: dimension sheet CC BY 4.0 (Xem Studio); files CC BY 4.0 or their publisher's license
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**Exact dimensions.** True size, with no tolerance added.

## Notes

- DIN 6798 covers serrated lock washers in form A (external teeth), form J (internal teeth) and form V (countersunk, external teeth). Engineers Edge's columns: bore d1, outside d2, d3, thicknesses s1 and s2, the thread diameter the washer is for, and the minimum number of teeth. The page's layout was garbled, so the mapping of d3 and s2 to form V is inferred and checked against McMaster-Carr: McMaster's countersunk (90°) external-tooth washers have OD 6.0, 8.0, 9.8, 11.8, 15.3, 19.0, 23.0 mm and thickness 0.2 to 0.3 mm for M3 to M12, equal to d3 (6, 8, 9.8, 11.8, 15.3, 19, 23) and s2 (0.2 to 0.4) for the same sizes.
- Number of teeth: the two sources disagree. Engineers Edge prints a minimum of 7 teeth up to size 3.2, 8 for 3.7 to 5.3, 9 for 6.4, 10 for 7.4 to 8.4, 12 for 10.5 and 12.5, 14 for 14.5 to 19, 16 for 21 to 25 and 18 for 28 and 31. GlobalFastener prints 9 teeth from M1.6 to M3, 10 for M3.5, 11 for M4 and M5, 12 for M6, 14 for M7 and M8, 16 for M10 and M12, 18 for M14 to M18, 20 for M20 to M24 and 22 for M27 and M30. Both are shown; the edition each one follows is not stated, so check the standard text.
- Bore: GlobalFastener and McMaster print 13 for M12, 17 for M16, 21 for M20 and 25 for M24 (and 15 for M14); Engineers Edge prints 12.5, 16.5, 21 (same) and 25 (same), with 14.5 for size 14. Sizes marked * are for hexagon head bolts only (Engineers Edge, citing DIN 6797). Hardness 350 to 425 HV10 (GlobalFastener).
- No model is drawn: the tooth profile (tooth width, set angle) is not published as numbers in the sources read. McMaster-Carr sells DIN 6798 lock washers with per-part STEP; its category is linked, not copied.

## Sizes

| source | thread | d1 (bore) | d2 / dc (outside) | d3 (form V outside) | s1 / t / thickness | s2 (form V) | teeth |
|---|---|---|---|---|---|---|---|
| Engineers Edge (forms A, J, V) | for thread 1.6 | 1.7 | 3.6 | — | 0.3 | — | 7 (min.) |
| Engineers Edge (forms A, J, V) | for thread 1.7 | 1.8 | 3.8 | — | 0.3 | — | 7 (min.) |
| Engineers Edge (forms A, J, V) | for thread 1.8 | 1.9 | 4 | — | 0.3 | — | 7 (min.) |
| Engineers Edge (forms A, J, V) | for thread 2 | 2.2 | 4.5 | 4.2 | 0.3 | 0.2 | 7 (min.) |
| Engineers Edge (forms A, J, V) | for thread 2.3 | 2.5 | 5 | — | 0.4 | 0.2 | 7 (min.) |
| Engineers Edge (forms A, J, V) | for thread 2.5 | 2.7 | 5.5 | 5.1 | 0.4 | 0.2 | 7 (min.) |
| Engineers Edge (forms A, J, V) | for thread 2.6 | 2.8 | 5.5 | — | 0.4 | 0.2 | 7 (min.) |
| Engineers Edge (forms A, J, V) | for thread 3 | 3.2 | 6 | 6 | 0.4 | 0.2 | 7 (min.) |
| Engineers Edge (forms A, J, V) | for thread 3.5 | 3.7 | 7 | 7 | 0.5 | 0.2 | 8 (min.) |
| Engineers Edge (forms A, J, V) | for thread 4 | 4.3 | 8 | 8 | 0.5 | 0.25 | 8 (min.) |
| Engineers Edge (forms A, J, V) | for thread 5 | 5.1* | 9 | — | 0.5 | 0.25 | 8 (min.) |
| Engineers Edge (forms A, J, V) | for thread 5 | 5.3 | 10 | 9.8 | 0.6 | — | 8 (min.) |
| Engineers Edge (forms A, J, V) | for thread 6 | 6.4 | 11 | 11.8 | 0.7 | 0.3 | 9 (min.) |
| Engineers Edge (forms A, J, V) | for thread 7 | 7.4 | 12.5 | — | 0.8 | 0.4 | 10 (min.) |
| Engineers Edge (forms A, J, V) | for thread 8 | 8.2* | 14 | — | 0.8 | — | 10 (min.) |
| Engineers Edge (forms A, J, V) | for thread 8 | 8.4 | 15 | 15.3 | 0.8 | — | 10 (min.) |
| Engineers Edge (forms A, J, V) | for thread 10 | 10.5 | 18 | 19 | 0.9 | 0.4 | 12 (min.) |
| Engineers Edge (forms A, J, V) | for thread 12 | 12.5 | 20.5 | 23 | 1 | 0.5 | 12 (min.) |
| Engineers Edge (forms A, J, V) | for thread 14 | 14.5 | 24 | 26.2 | 1 | 0.5 | 14 (min.) |
| Engineers Edge (forms A, J, V) | for thread 16 | 16.5 | 26 | 30.2 | 1.2 | 0.6 | 14 (min.) |
| Engineers Edge (forms A, J, V) | for thread 18 | 19 | 30 | — | 1.4 | 0.6 | 14 (min.) |
| Engineers Edge (forms A, J, V) | for thread 20 | 21 | 33 | — | 1.4 | — | 16 (min.) |
| Engineers Edge (forms A, J, V) | for thread 22 | 23 | 36 | — | 1.5 | — | 16 (min.) |
| Engineers Edge (forms A, J, V) | for thread 24 | 25 | 38 | — | 1.5 | — | 16 (min.) |
| Engineers Edge (forms A, J, V) | for thread 27 | 28 | 44 | — | 1.6 | — | 18 (min.) |
| Engineers Edge (forms A, J, V) | for thread 30 | 31 | 48 | — | 1.6 | — | 18 (min.) |
| GlobalFastener (form A, external teeth) | M1.6 | 1.7 (d max 1.84) | 3.6 / 3.3 | — | 0.3 | — | 9 (min.) |
| GlobalFastener (form A, external teeth) | M2 | 2.2 (d max 2.34) | 4.5 / 4.2 | — | 0.3 | — | 9 (min.) |
| GlobalFastener (form A, external teeth) | M2.5 | 2.7 (d max 2.84) | 5.5 / 5.2 | — | 0.4 | — | 9 (min.) |
| GlobalFastener (form A, external teeth) | M3 | 3.2 (d max 3.38) | 6 / 5.7 | — | 0.4 | — | 9 (min.) |
| GlobalFastener (form A, external teeth) | M3.5 | 3.7 (d max 3.88) | 7 / 6.64 | — | 0.5 | — | 10 (min.) |
| GlobalFastener (form A, external teeth) | M4 | 4.3 (d max 4.48) | 8 / 7.64 | — | 0.5 | — | 11 (min.) |
| GlobalFastener (form A, external teeth) | M5 | 5.3 (d max 5.48) | 10 / 9.64 | — | 0.6 | — | 11 (min.) |
| GlobalFastener (form A, external teeth) | M6 | 6.4 (d max 6.62) | 11 / 10.57 | — | 0.7 | — | 12 (min.) |
| GlobalFastener (form A, external teeth) | M7 | 7.4 (d max 7.62) | 12.5 / 12.07 | — | 0.8 | — | 14 (min.) |
| GlobalFastener (form A, external teeth) | M8 | 8.4 (d max 8.62) | 15 / 14.57 | — | 0.8 | — | 14 (min.) |
| GlobalFastener (form A, external teeth) | M10 | 10.5 (d max 10.77) | 18 / 17.57 | — | 0.9 | — | 16 (min.) |
| GlobalFastener (form A, external teeth) | M12 | 13 (d max 13.27) | 20.5 / 19.98 | — | 1 | — | 16 (min.) |
| GlobalFastener (form A, external teeth) | M14 | 15 (d max 15.27) | 24 / 23.48 | — | 1 | — | 18 (min.) |
| GlobalFastener (form A, external teeth) | M16 | 17 (d max 17.27) | 26 / 25.48 | — | 1.2 | — | 18 (min.) |
| GlobalFastener (form A, external teeth) | M18 | 19 (d max 19.33) | 30 / 29.48 | — | 1.4 | — | 18 (min.) |
| GlobalFastener (form A, external teeth) | M20 | 21 (d max 21.33) | 33 / 32.38 | — | 1.4 | — | 20 (min.) |
| GlobalFastener (form A, external teeth) | M22 | 23 (d max 23.33) | 36 / 35.38 | — | 1.5 | — | 20 (min.) |
| GlobalFastener (form A, external teeth) | M24 | 25 (d max 25.33) | 38 / 37.38 | — | 1.5 | — | 20 (min.) |
| GlobalFastener (form A, external teeth) | M27 | 28 (d max 28.33) | 44 / 43.38 | — | 1.6 | — | 22 (min.) |
| GlobalFastener (form A, external teeth) | M30 | 31 (d max 31.39) | 48 / 47.38 | — | 1.6 | — | 22 (min.) |
| McMaster-Carr, 18-8 external tooth | M2 | 2.2 | 4.5 | — | 0.2 to 0.4 | — | not printed |
| McMaster-Carr, 18-8 external tooth | M2.5 | 2.7 | 5.5 | — | 0.3 to 0.5 | — | not printed |
| McMaster-Carr, 18-8 external tooth | M3 | 3.2 | 6 | — | 0.3 to 0.5 | — | not printed |
| McMaster-Carr, 18-8 external tooth | M4 | 4.3 | 8 | — | 0.4 to 0.6 | — | not printed |
| McMaster-Carr, 18-8 external tooth | M5 | 5.3 | 10 | — | 0.5 to 0.7 | — | not printed |
| McMaster-Carr, 18-8 external tooth | M6 | 6.4 | 11 | — | 0.6 to 0.8 | — | not printed |
| McMaster-Carr, 18-8 external tooth | M8 | 8.4 | 15 | — | 0.7 to 0.9 | — | not printed |
| McMaster-Carr, 18-8 external tooth | M10 | 10.5 | 18 | — | 0.8 to 1.0 | — | not printed |
| McMaster-Carr, 18-8 external tooth | M12 | 13 | 20.5 | — | 0.9 to 1.2 | — | not printed |
| McMaster-Carr, 18-8 external tooth | M16 | 17 | 26 | — | 1.0 to 1.4 | — | not printed |
| McMaster-Carr, 18-8 external tooth | M20 | 21 | 33 | — | 1.2 to 1.5 | — | not printed |
| McMaster-Carr, 18-8 external tooth | M24 | 25 | 38 | — | 1.4 to 1.6 | — | not printed |

## Where the files are

- Engineers Edge: [DIN 6798 serrated lock washers: d1, d2, d3, s1, s2, thread diameter, minimum teeth, weight (forms A, J, V)](https://ns2.engineersedge.com/hardware/din_6798_serrated_lock_washers_14593.htm) — web — Publisher's page; dimensions are facts
- GlobalFastener: [DIN 6798 form A (external teeth): d, dc max / min, t, minimum teeth, M1.6 to M30](https://www.globalfastener.com/standards/detail_639.html) — web — Publisher's page; dimensions are facts
- McMaster-Carr: [DIN 6798 lock washers (free STEP/IGES per part, for your own design use; no redistribution)](https://www.mcmaster.com/din-6798-lock-washers) — STEP, IGES, PDF — McMaster-Carr site terms: personal design use, no redistribution (verify at link)

## Questions

**What is the outside diameter of an M6 DIN 6798 A washer?**

11 mm (Engineers Edge d2 and GlobalFastener dc max), 10.57 mm minimum; bore 6.4 mm, thickness 0.7 mm (McMaster 0.6 to 0.8).

**How many teeth does an M6 serrated lock washer have?**

Engineers Edge prints 9 minimum, GlobalFastener 12 minimum. The sources disagree; check the standard edition.

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