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Woodruff keys, metric (DIN 6888 / ISO 3912): b × h × d2, keyseat depths t1 and t2, shaft ranges
What are the dimensions of a metric Woodruff key (DIN 6888) such as 5 × 6.5 × 16, and the shaft and hub keyseat depths? · Standard part · basis: DIN 6888 tables as published by OPAC (b, h, d2, t1, t2) and fasten.it (shaft ranges, l), checked against McMaster-Carr; ISO 3912 limits from fasten.it
Also called: din 6888, iso 3912, half moon key, woodruff key din 6888, woodruff key metric, woodruff key 5x6.5, woodruff key 4x6.5x16, scheibenfeder, woodruff key size chart mm, woodruff keyseat depth mm, woodruff key step, woodruff cutter metric, keyseat cutter size
Exact dimensions. True size, with no printing tolerance added.
- sizes
- 24 in table
Notes
- Metric Woodruff keys are named b × h × d2: width, height, disc diameter. The key is the segment of a disc of diameter d2 that stands h above the bottom of the arc, with a flat top. The printed length l is the flat's chord: l = 2·√(R² − (R − h)²) with R = d2/2. That equation reproduces the tabulated l for all 24 sizes (to 0.01 mm), so the key files are drawn exactly that way.
- Two series (A and B) share each key size but sit on different shaft ranges, so the keyseat depth differs: the deeper seat (series B) goes with the larger shaft range. A dash means the size has no series A range. In both series the seat depths add up the same way: t1 + t2 = h + 0.2 mm, which holds for every row.
- Files: 24 key solids and 24 example shafts with the keyseat cut at t1 (series A where it exists, otherwise B). The example shaft is the largest diameter of that series' range ('38+' is drawn as 38 mm), is 2 shaft diameters long, and the seat is a circle of d2 and width b, bottom t1 below the top line of the shaft. The hub seat depth t2 is in the table only. Tolerances (b h9, h h12) are in the standard, not in the files.
- Status: fasten.it marks DIN 6888 (edition 08/1956) as cancelled; ISO 3912 (1977) covers 16 of these 24 sizes (marked in the table). The depths come from one maker's table (OPAC) and are checked by the t1 + t2 = h + 0.2 identity; width, height, d2 and l agree across OPAC, fasten.it and McMaster. Shaft ranges are from fasten.it only.
- Left out: edge chamfers or radii, which the sources do not give; the 3 × 5 × 13 and 6 × 10 × 25 sizes are marked outside the DIN list on OPAC's page but are listed on fasten.it and McMaster, so they are kept in the table and files.
Woodruff keys, metric (DIN 6888 / ISO 3912): b × h × d2, keyseat… size chart
| b × h × d2, mm | chord length l, mm | shaft d1, series A / B, mm | shaft seat depth t1, A / B, mm | hub seat depth t2, A / B, mm | also in ISO 3912 |
|---|---|---|---|---|---|
| 1 × 1.4 × 4 | 3.82 | 3–4 / 6–8 | 1 / 1 | 0.6 / 0.6 | yes |
| 1.5 × 2.6 × 7 | 6.76 | 4–6 / 8–10 | 2 / 2 | 0.8 / 0.8 | yes |
| 2 × 2.6 × 7 | 6.76 | 6–8 / 10–12 | 1.8 / 1.8 | 1 / 1 | yes |
| 2 × 3.7 × 10 | 9.66 | 6–8 / 10–12 | 2.9 / 2.9 | 1 / 1 | yes |
| 2.5 × 3.7 × 10 | 9.66 | 8–10 / 12–17 | 2.9 / 2.9 | 1 / 1 | yes |
| 3 × 3.7 × 10 | 9.66 | 8–10 / 12–17 | 2.5 / 2.8 | 1.4 / 1.1 | DIN only |
| 3 × 5 × 13 | 12.65 | 8–10 / 12–17 | 3.8 / 4.1 | 1.4 / 1.1 | yes |
| 3 × 6.5 × 16 | 15.72 | – / 12–17 | 5.3 / 5.6 | 1.4 / 1.1 | yes |
| 4 × 5 × 13 | 12.65 | 10–12 / 17–22 | 3.5 / 4.1 | 1.7 / 1.1 | DIN only |
| 4 × 6.5 × 16 | 15.72 | 10–12 / 17–22 | 5 / 5.6 | 1.7 / 1.1 | yes |
| 4 × 7.5 × 19 | 18.57 | – / 17–22 | 6 / 6.6 | 1.7 / 1.1 | yes |
| 5 × 6.5 × 16 | 15.72 | 12–17 / 22–30 | 4.5 / 5.4 | 2.2 / 1.3 | yes |
| 5 × 7.5 × 19 | 18.57 | 12–17 / 22–30 | 5.5 / 6.4 | 2.2 / 1.3 | yes |
| 5 × 9 × 22 | 21.63 | – / 22–30 | 7 / 7.9 | 2.2 / 1.3 | yes |
| 6 × 7.5 × 19 | 18.57 | 17–22 / 22–30 | 5.1 / 6 | 2.6 / 1.7 | DIN only |
| 6 × 9 × 22 | 21.63 | 17–22 / 30–38 | 6.6 / 7.5 | 2.6 / 1.7 | yes |
| 6 × 10 × 25 | 24.49 | 17–22 / 30–38 | 7.6 / 8.5 | 2.6 / 1.7 | yes |
| 6 × 11 × 28 | 27.35 | – / 30–38 | 8.6 / 9.5 | 2.6 / 1.7 | DIN only |
| 8 × 9 × 22 | 21.63 | 22–30 / 38+ | 6.2 / 7.5 | 3 / 1.7 | DIN only |
| 8 × 11 × 28 | 27.35 | 22–30 / 38+ | 8.2 / 9.5 | 3 / 1.7 | yes |
| 8 × 13 × 32 | 31.43 | – / 38+ | 10.2 / 11.5 | 3 / 1.7 | DIN only |
| 10 × 11 × 28 | 27.35 | 30–38 / 38+ | 7.8 / 9.1 | 3.4 / 2.1 | DIN only |
| 10 × 13 × 32 | 31.43 | 30–38 / 38+ | 9.8 / 11.1 | 3.4 / 2.1 | yes |
| 10 × 16 × 45 | 43.08 | – / 38+ | 12.8 / 14.1 | 3.4 / 2.1 | DIN only |
Where the files are
Other publishers' files are linked, not hosted. "verify" = check the license at the link before commercial use.
| OPAC | DIN 6888 Woodruff keys: b x h x d2 with keyway depths t1 (shaft) and t2 (hub), series A and B | web | Publisher's page; dimensions are facts |
| fasten.it | DIN 6888 Standard dimensions for Woodruff keys: b, h, shaft diameters d1 (form A / B), d2, l | web | Publisher's page; dimensions are facts |
| fasten.it | ISO 3912 Woodruff keys: limits on b, h, d2 | web | Publisher's page; dimensions are facts |
| McMaster-Carr | Woodruff keys: inch key sizes (width, diameter, height, length) and metric sizes | web | Publisher's page; dimensions are facts |
Free files
★ Free files 48 parts. Generated by Xem Studio from the standard; threads are plain cylinders at major diameter. CC BY 4.0. index.json
| woodruff-key-1x1-4x4 | Woodruff key 1 × 1.4 × 4 mm (b × h × d2): width 1, height 1.4, disc diameter 4; chord 3.82 mm; nominal values, no edge breaks | STEP · STL |
| woodruff-keyseat-1x1-4x4-shaft-4mm-series-a | Shaft keyseat for 1 × 1.4 × 4: example shaft ⌀4 mm (top of the series A range 3 to 4 mm) × 8 mm long, circular seat ⌀4 × 1 wide, bottom 1 mm (t1, series A) below the top line | STEP · STL |
| woodruff-key-1-5x2-6x7 | Woodruff key 1.5 × 2.6 × 7 mm (b × h × d2): width 1.5, height 2.6, disc diameter 7; chord 6.76 mm; nominal values, no edge breaks | STEP · STL |
| woodruff-keyseat-1-5x2-6x7-shaft-6mm-series-a | Shaft keyseat for 1.5 × 2.6 × 7: example shaft ⌀6 mm (top of the series A range 4 to 6 mm) × 12 mm long, circular seat ⌀7 × 1.5 wide, bottom 2 mm (t1, series A) below the top line | STEP · STL |
| woodruff-key-2x2-6x7 | Woodruff key 2 × 2.6 × 7 mm (b × h × d2): width 2, height 2.6, disc diameter 7; chord 6.76 mm; nominal values, no edge breaks | STEP · STL |
| woodruff-keyseat-2x2-6x7-shaft-8mm-series-a | Shaft keyseat for 2 × 2.6 × 7: example shaft ⌀8 mm (top of the series A range 6 to 8 mm) × 16 mm long, circular seat ⌀7 × 2 wide, bottom 1.8 mm (t1, series A) below the top line | STEP · STL |
| woodruff-key-2x3-7x10 | Woodruff key 2 × 3.7 × 10 mm (b × h × d2): width 2, height 3.7, disc diameter 10; chord 9.66 mm; nominal values, no edge breaks | STEP · STL |
| woodruff-keyseat-2x3-7x10-shaft-8mm-series-a | Shaft keyseat for 2 × 3.7 × 10: example shaft ⌀8 mm (top of the series A range 6 to 8 mm) × 16 mm long, circular seat ⌀10 × 2 wide, bottom 2.9 mm (t1, series A) below the top line | STEP · STL |
| woodruff-key-2-5x3-7x10 | Woodruff key 2.5 × 3.7 × 10 mm (b × h × d2): width 2.5, height 3.7, disc diameter 10; chord 9.66 mm; nominal values, no edge breaks | STEP · STL |
| woodruff-keyseat-2-5x3-7x10-shaft-10mm-series-a | Shaft keyseat for 2.5 × 3.7 × 10: example shaft ⌀10 mm (top of the series A range 8 to 10 mm) × 20 mm long, circular seat ⌀10 × 2.5 wide, bottom 2.9 mm (t1, series A) below the top line | STEP · STL |
| woodruff-key-3x3-7x10 | Woodruff key 3 × 3.7 × 10 mm (b × h × d2): width 3, height 3.7, disc diameter 10; chord 9.66 mm; nominal values, no edge breaks | STEP · STL |
| woodruff-keyseat-3x3-7x10-shaft-10mm-series-a | Shaft keyseat for 3 × 3.7 × 10: example shaft ⌀10 mm (top of the series A range 8 to 10 mm) × 20 mm long, circular seat ⌀10 × 3 wide, bottom 2.5 mm (t1, series A) below the top line | STEP · STL |
| woodruff-key-3x5x13 | Woodruff key 3 × 5 × 13 mm (b × h × d2): width 3, height 5, disc diameter 13; chord 12.65 mm; nominal values, no edge breaks | STEP · STL |
| woodruff-keyseat-3x5x13-shaft-10mm-series-a | Shaft keyseat for 3 × 5 × 13: example shaft ⌀10 mm (top of the series A range 8 to 10 mm) × 20 mm long, circular seat ⌀13 × 3 wide, bottom 3.8 mm (t1, series A) below the top line | STEP · STL |
| woodruff-key-3x6-5x16 | Woodruff key 3 × 6.5 × 16 mm (b × h × d2): width 3, height 6.5, disc diameter 16; chord 15.72 mm; nominal values, no edge breaks | STEP · STL |
| woodruff-keyseat-3x6-5x16-shaft-17mm-series-b | Shaft keyseat for 3 × 6.5 × 16: example shaft ⌀17 mm (top of the series B range 12 to 17 mm) × 34 mm long, circular seat ⌀16 × 3 wide, bottom 5.6 mm (t1, series B) below the top line | STEP · STL |
| woodruff-key-4x5x13 | Woodruff key 4 × 5 × 13 mm (b × h × d2): width 4, height 5, disc diameter 13; chord 12.65 mm; nominal values, no edge breaks | STEP · STL |
| woodruff-keyseat-4x5x13-shaft-12mm-series-a | Shaft keyseat for 4 × 5 × 13: example shaft ⌀12 mm (top of the series A range 10 to 12 mm) × 24 mm long, circular seat ⌀13 × 4 wide, bottom 3.5 mm (t1, series A) below the top line | STEP · STL |
| woodruff-key-4x6-5x16 | Woodruff key 4 × 6.5 × 16 mm (b × h × d2): width 4, height 6.5, disc diameter 16; chord 15.72 mm; nominal values, no edge breaks | STEP · STL |
| woodruff-keyseat-4x6-5x16-shaft-12mm-series-a | Shaft keyseat for 4 × 6.5 × 16: example shaft ⌀12 mm (top of the series A range 10 to 12 mm) × 24 mm long, circular seat ⌀16 × 4 wide, bottom 5 mm (t1, series A) below the top line | STEP · STL |
| woodruff-key-4x7-5x19 | Woodruff key 4 × 7.5 × 19 mm (b × h × d2): width 4, height 7.5, disc diameter 19; chord 18.57 mm; nominal values, no edge breaks | STEP · STL |
| woodruff-keyseat-4x7-5x19-shaft-22mm-series-b | Shaft keyseat for 4 × 7.5 × 19: example shaft ⌀22 mm (top of the series B range 17 to 22 mm) × 44 mm long, circular seat ⌀19 × 4 wide, bottom 6.6 mm (t1, series B) below the top line | STEP · STL |
| woodruff-key-5x6-5x16 | Woodruff key 5 × 6.5 × 16 mm (b × h × d2): width 5, height 6.5, disc diameter 16; chord 15.72 mm; nominal values, no edge breaks | STEP · STL |
| woodruff-keyseat-5x6-5x16-shaft-17mm-series-a | Shaft keyseat for 5 × 6.5 × 16: example shaft ⌀17 mm (top of the series A range 12 to 17 mm) × 34 mm long, circular seat ⌀16 × 5 wide, bottom 4.5 mm (t1, series A) below the top line | STEP · STL |
| woodruff-key-5x7-5x19 | Woodruff key 5 × 7.5 × 19 mm (b × h × d2): width 5, height 7.5, disc diameter 19; chord 18.57 mm; nominal values, no edge breaks | STEP · STL |
| woodruff-keyseat-5x7-5x19-shaft-17mm-series-a | Shaft keyseat for 5 × 7.5 × 19: example shaft ⌀17 mm (top of the series A range 12 to 17 mm) × 34 mm long, circular seat ⌀19 × 5 wide, bottom 5.5 mm (t1, series A) below the top line | STEP · STL |
| woodruff-key-5x9x22 | Woodruff key 5 × 9 × 22 mm (b × h × d2): width 5, height 9, disc diameter 22; chord 21.63 mm; nominal values, no edge breaks | STEP · STL |
| woodruff-keyseat-5x9x22-shaft-30mm-series-b | Shaft keyseat for 5 × 9 × 22: example shaft ⌀30 mm (top of the series B range 22 to 30 mm) × 60 mm long, circular seat ⌀22 × 5 wide, bottom 7.9 mm (t1, series B) below the top line | STEP · STL |
| woodruff-key-6x7-5x19 | Woodruff key 6 × 7.5 × 19 mm (b × h × d2): width 6, height 7.5, disc diameter 19; chord 18.57 mm; nominal values, no edge breaks | STEP · STL |
| woodruff-keyseat-6x7-5x19-shaft-22mm-series-a | Shaft keyseat for 6 × 7.5 × 19: example shaft ⌀22 mm (top of the series A range 17 to 22 mm) × 44 mm long, circular seat ⌀19 × 6 wide, bottom 5.1 mm (t1, series A) below the top line | STEP · STL |
| woodruff-key-6x9x22 | Woodruff key 6 × 9 × 22 mm (b × h × d2): width 6, height 9, disc diameter 22; chord 21.63 mm; nominal values, no edge breaks | STEP · STL |
| woodruff-keyseat-6x9x22-shaft-22mm-series-a | Shaft keyseat for 6 × 9 × 22: example shaft ⌀22 mm (top of the series A range 17 to 22 mm) × 44 mm long, circular seat ⌀22 × 6 wide, bottom 6.6 mm (t1, series A) below the top line | STEP · STL |
| woodruff-key-6x10x25 | Woodruff key 6 × 10 × 25 mm (b × h × d2): width 6, height 10, disc diameter 25; chord 24.49 mm; nominal values, no edge breaks | STEP · STL |
| woodruff-keyseat-6x10x25-shaft-22mm-series-a | Shaft keyseat for 6 × 10 × 25: example shaft ⌀22 mm (top of the series A range 17 to 22 mm) × 44 mm long, circular seat ⌀25 × 6 wide, bottom 7.6 mm (t1, series A) below the top line | STEP · STL |
| woodruff-key-6x11x28 | Woodruff key 6 × 11 × 28 mm (b × h × d2): width 6, height 11, disc diameter 28; chord 27.35 mm; nominal values, no edge breaks | STEP · STL |
| woodruff-keyseat-6x11x28-shaft-38mm-series-b | Shaft keyseat for 6 × 11 × 28: example shaft ⌀38 mm (top of the series B range 30 to 38 mm) × 76 mm long, circular seat ⌀28 × 6 wide, bottom 9.5 mm (t1, series B) below the top line | STEP · STL |
| woodruff-key-8x9x22 | Woodruff key 8 × 9 × 22 mm (b × h × d2): width 8, height 9, disc diameter 22; chord 21.63 mm; nominal values, no edge breaks | STEP · STL |
| woodruff-keyseat-8x9x22-shaft-30mm-series-a | Shaft keyseat for 8 × 9 × 22: example shaft ⌀30 mm (top of the series A range 22 to 30 mm) × 60 mm long, circular seat ⌀22 × 8 wide, bottom 6.2 mm (t1, series A) below the top line | STEP · STL |
| woodruff-key-8x11x28 | Woodruff key 8 × 11 × 28 mm (b × h × d2): width 8, height 11, disc diameter 28; chord 27.35 mm; nominal values, no edge breaks | STEP · STL |
| woodruff-keyseat-8x11x28-shaft-30mm-series-a | Shaft keyseat for 8 × 11 × 28: example shaft ⌀30 mm (top of the series A range 22 to 30 mm) × 60 mm long, circular seat ⌀28 × 8 wide, bottom 8.2 mm (t1, series A) below the top line | STEP · STL |
| woodruff-key-8x13x32 | Woodruff key 8 × 13 × 32 mm (b × h × d2): width 8, height 13, disc diameter 32; chord 31.43 mm; nominal values, no edge breaks | STEP · STL |
| woodruff-keyseat-8x13x32-shaft-38mm-series-b | Shaft keyseat for 8 × 13 × 32: example shaft ⌀38 mm (top of the series B range 38+ mm) × 76 mm long, circular seat ⌀32 × 8 wide, bottom 11.5 mm (t1, series B) below the top line | STEP · STL |
| woodruff-key-10x11x28 | Woodruff key 10 × 11 × 28 mm (b × h × d2): width 10, height 11, disc diameter 28; chord 27.35 mm; nominal values, no edge breaks | STEP · STL |
| woodruff-keyseat-10x11x28-shaft-38mm-series-a | Shaft keyseat for 10 × 11 × 28: example shaft ⌀38 mm (top of the series A range 30 to 38 mm) × 76 mm long, circular seat ⌀28 × 10 wide, bottom 7.8 mm (t1, series A) below the top line | STEP · STL |
| woodruff-key-10x13x32 | Woodruff key 10 × 13 × 32 mm (b × h × d2): width 10, height 13, disc diameter 32; chord 31.43 mm; nominal values, no edge breaks | STEP · STL |
| woodruff-keyseat-10x13x32-shaft-38mm-series-a | Shaft keyseat for 10 × 13 × 32: example shaft ⌀38 mm (top of the series A range 30 to 38 mm) × 76 mm long, circular seat ⌀32 × 10 wide, bottom 9.8 mm (t1, series A) below the top line | STEP · STL |
| woodruff-key-10x16x45 | Woodruff key 10 × 16 × 45 mm (b × h × d2): width 10, height 16, disc diameter 45; chord 43.08 mm; nominal values, no edge breaks | STEP · STL |
| woodruff-keyseat-10x16x45-shaft-38mm-series-b | Shaft keyseat for 10 × 16 × 45: example shaft ⌀38 mm (top of the series B range 38+ mm) × 76 mm long, circular seat ⌀45 × 10 wide, bottom 14.1 mm (t1, series B) below the top line | STEP · STL |
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Fits with
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Questions
What are the dimensions of a 5 × 6.5 × 16 Woodruff key?
5 mm wide, 6.5 mm tall, 16 mm disc diameter, 15.72 mm long. Shaft seat 4.5 mm deep (series A, shaft 12 to 17 mm) or 5.4 mm (series B, 22 to 30 mm); hub seat 2.2 / 1.3 mm.
How is the chord length of a Woodruff key found?
l = 2·√(R² − (R − h)²), R = d2/2: for 5 × 6.5 × 16 that is 2·√(64 − 2.25) = 15.72 mm.
Which Woodruff keys are in ISO 3912?
16 of the 24 DIN 6888 sizes: the table marks them.