SPR-009Engineering model

Cold-coiled extension

Springs

Scope and limits

Cold-coiled extension — geometry, declared design limits and explicit qualification gaps. Cylindrical round wire, axial load, linear elastic body after coils separate. Initial tension must be declared. Hook stresses and hook compliance are excluded. Material/heat treatment, tolerances, surface condition, residual stress, relaxation, corrosion, operating temperature, fatigue life and production tests remain unverified.

Standards and references

DIN EN 13906-2:2013-09

Cylindrical helical extension spring design

Source scope: Axially loaded round-wire cylindrical extension. Public cold scope: d ≤ 20 mm, active turns ≥ 3, index 4–20; hot: d ≥ 10 mm, turns ≥ 3, index 4–12.
Implementation in Prufi: Public dimensional scope implemented from declared design data. Hook/eye stress, initial-tension manufacture, temperature suitability and full normative verification remain unassessed.

ISO 22705-2:2023

Spring measurement and testing: cold-formed extension

Source scope: Cold-formed round-wire helical extension measurement; dynamic testing excluded.
Implementation in Prufi: Measurement context only. Physical test procedures and acceptance are unassessed.

STEP examples for this check

No public STEP example is currently assigned to this check.

Browse all public examples