DEMO — fictional range. Local brief only, NOT SENT. No personal data is collected or transmitted.
MATERIAL
Six materials, and what each one is chosen for.
In a connector the materials are chosen for the contact first and for everything else second, because the contact is the only part carrying current.
Illustrative material record
- Brass, nickel plated
- Shells and bodies · machines well, the plating is the corrosion protection
- Copper alloy
- Contact bodies · carries current, needs a plating to resist wear and oxide
- Gold over nickel
- Contact plating · stable and low resistance, thin and expensive
- Tin over nickel
- Contact plating · cheap and solderable, oxides form and needs wiping
- Polyamide
- Bodies and inserts · moulds accurately, takes the rating, absorbs moisture
- Silicone
- Seals and gaskets · stays flexible across temperature, ages in sunlight
Illustrative examples for a fictional range. Material selection depends on the current, the environment and the mating cycles, and is confirmed against a specification rather than a web page.
Why the contact metal is not the contact surface.
Because the surface is the plating. The copper alloy carries the current, but what touches the other half is gold or tin, and it is the plating that decides the resistance and the life.
Why polyamide absorbs moisture.
Because it changes the dimension and the electrical properties. A block that meets its rating dry may not meet it in a humid enclosure, and the change is reversible but slow.