A good contact spring specification starts with the working position, not the free shape. Engineers should define normal force at the real contact point, allowable resistance window, current level, and the mechanical travel that the contact will see during insertion, vibration, and long-term service.
Material and plating decisions should match the environment. Humidity, fretting, contamination, temperature rise, and mating cycles all change what is acceptable. A spring that passes an initial resistance reading may still become unstable if the plating stack, base material hardness, or contact geometry are not aligned with the application.
Tolerance control is equally important. Contact springs are often small parts inside larger assemblies, so retention features, housing stiffness, and the mating interface can all shift the delivered force. The drawing package should therefore tie force test method, contact zone inspection, and assembly reference dimensions together instead of listing only nominal shape.
Validation should be written into the specification before tooling release. For most production programs that means defining the force fixture, the resistance test method, the number of mating cycles, and any vibration or temperature exposure that the contact must survive. Without those items, suppliers and buyers may both believe the drawing is complete while measuring different things.