DIN 660Round head

DIN 660 2.5 × 5 Round head

DIN 660 2.5 × 5 is a round head rivet with a 5 mm nominal length, 2.5 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.

Dimensioned drawing — DIN 660 2.5 × 5⌀d2 4.4k 1.5l 5⌀d3 2.37
DIN 660 2.5 × 5 — Round headNominal dimensions in mm · Not to scale
Diameter2.5 mm
Length5 mm
HeadRound head

Dimensions

Standard
DIN 660
Type
Round head rivet
Size
2.5 × 5
Diameter
2.5
Length L
5 mm
Head diameter d2
4.4 mm
Shank diameter d3 min.
2.37 mm
Head height k
1.5 mm
Hole diameter dH12
2.6 mm
Head
Round head

Nominal values in millimetres as published in DIN 660. Estimated weight 0.296 g per piece in steel (0.298 g in stainless), calculated from the nominal geometry — real parts vary with tolerance and head chamfers.

Other lengthsDIN 660 2.5

All 2.5 specifications

Choosing and fitting this size

DIN 660 2.5 × 5 is a round head with a 2.5 mm shank, 5 mm long under the head. The hole is drilled 2.6 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.