DIN 660 8 × 25 Round head
DIN 660 8 × 25 is a round head rivet with a 25 mm nominal length, 8 mm shank diameter. A solid rivet with a domed head. The shank goes through a drilled hole and the protruding end is deformed — cold at these sizes — into a second head, so the joint is permanent: removing the rivet destroys it. Nominal diameters run from 1 to 8 mm and the standard prints a mass for every length it makes, which is why the length lists on these pages differ from diameter to diameter rather than running as one block. The sizes in brackets — 1.4, 3.5 and 7 mm — are the standard's non-preferred sizes; they are tabulated all the same, because they are made and sold.
Dimensions
- Standard
- DIN 660
- Type
- Round head rivet
- Size
- 8 × 25
- Diameter
- 8
- Length L
- 25 mm
- Head diameter d2
- 14 mm
- Shank diameter d3 min.
- 7.76 mm
- Head height k
- 4.8 mm
- Hole diameter dH12
- 8.4 mm
- Head
- Round head
Nominal values in millimetres as published in DIN 660. Estimated weight 13.219 g per piece in steel (13.304 g in stainless), calculated from the nominal geometry — real parts vary with tolerance and head chamfers.
Other lengthsDIN 660 8
All 8 specificationsChoosing and fitting this size
DIN 660 8 × 25 is a round head with a 8 mm shank, 25 mm long under the head. The hole is drilled 8.4 mm — slightly larger than the shank, so the rivet drops in without force. Setting upsets the protruding end into a second head, which makes the joint permanent: there is no way to take it apart without destroying the rivet.
Rivets carry no property class. The standard sets a minimum tensile strength per material group instead of a single grade, and the material is part of the designation — St for steel, A2 or A4 for stainless — so the strength of a rivet is a property of the wire it was made from rather than of a marking on the head. Cold setting work-hardens the shank as it upsets, which is why a properly set joint is stronger than the annealed rivet that went into it; it also means the rivet cannot be straightened and re-used after a bad set.