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Spherical Washer and Conical Seat Dimensions (DIN 6319, M6 to M48)
Guide · Updated October 28, 2026
DIN 6319 covers spherical washers (form C) and conical seats (form D, d3 = d2), M6 to M48. Values agree across fasteners.eu, Ganter, Elesa and JW Winco DIN 6319 tables. Bores d1 and d2 are H13.
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Step by step
- Find the screw size: Pick the row for your screw, M6 to M48.
- Pick the pair: Use a form C spherical washer with a form D conical seat of the same size; both share the outside diameter.
- Check the bores: Form C bore d1 and form D bore d2 are H13, e.g. 10.5 and 12 mm for M10.
- Check the stack: The pair nests, so the assembled height is less than h2 + h3; check the catalog assembled height.
DIN 6319 spherical washer and conical seat dimensions (mm)
Columns: screw size; form C bore d1, outside d3, height h2, sphere radius r; form D bore d2, outside d3, seat diameter d5, height h3.
- Size | C d1 | C d3 | C h2 | r | D d2 | D d3 | D d5 | D h3
- M6 | 6.4 | 12 | 2.3 | 9 | 7.1 | 12 | 11 | 2.8
- M8 | 8.4 | 17 | 3.2 | 12 | 9.6 | 17 | 14.5 | 3.5
- M10 | 10.5 | 21 | 4 | 15 | 12 | 21 | 18.5 | 4.2
- M12 | 13 | 24 | 4.6 | 17 | 14.2 | 24 | 20 | 5
- M14 | 15 | 28 | 5 | 22 | 16.5 | 28 | 24.8 | 5.6
- M16 | 17 | 30 | 5.3 | 22 | 19 | 30 | 26 | 6.2
- M20 | 21 | 36 | 6.3 | 27 | 23.2 | 36 | 31 | 7.5
- M24 | 25 | 44 | 8.2 | 32 | 28 | 44 | 37 | 9.5
- M30 | 31 | 56 | 11.2 | 41 | 35 | 56 | 49 | 12
- M36 | 37 | 68 | 14 | 50 | 42 | 68 | 60 | 15
- M42 | 43 | 78 | 17 | 58 | 49 | 78 | 70 | 18
- M48 | 50 | 92 | 21 | 67 | 56 | 92 | 82 | 22
Worked example: M12 pair
For M12, the form C washer has a 13 mm bore, 24 mm outside and is 4.6 mm tall with a 17 mm sphere radius. The form D seat has a 14.2 mm bore, 24 mm outside and is 5 mm tall. Assembled, the pair is about 8 mm tall (catalog value), not the 9.6 mm sum, because the washer nests in the seat.
Common problems
- Screw length off: the pair nests; use the assembled height, not h2 + h3.
- Washer will not tilt: form C and D must be the same size.
- Seat on a slot: form D is for plain round holes; use a larger-OD seat for slots.
FAQ
What are DIN 6319 washers for?
Clamping on surfaces that are not parallel; the spherical washer rocks in the conical seat.
What is form G?
A conical seat with a larger outside diameter, mainly for slotted holes. It is not in this chart.
Why is the form D bore bigger?
The seat bore d2 is larger than the washer bore d1 so the washer can tilt, e.g. 14.2 vs 13 mm for M12.
Are load ratings shown?
No; catalogs give different maximum bolt forces, so check your supplier.
Related guides and calculators
- Spherical seat nuts (DIN 6330)
- Clamping washers (DIN 6340)
- Shim rings (DIN 988)
- T-slot nuts (DIN 508)
- All free machinist calculators
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