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# Electrical Spring Contacts Material Selection

## Electrical Spring Contacts Material Selection

(OP)
Hi to all,

I want to make a custom electrical spring contact.
From what i know the material used for electrical spring contacts is some kind of Ti-Cu alloy (couldn't find anything specific) and i was wondering if it is possible to match, to some degree, the properties of commercial spring steel (or any other suitable, not to costly, material) to the Ti-Cu alloy properties, especially the elasticity.

I'm asking because i got a prototype of the spring contact made from Nickel Plated Spring Steel but the material is too brittle for the application i need, and i fiddled with Shield Finger contact and although it is only 0.1 mm thick the part is very elastic and robust, as it is paper thin and makes the impression that it will crumple as soon as you touch it.

Thanks.

### RE: Electrical Spring Contacts Material Selection

Be-Cu material is preferred for such applications.

"Even,if you are a minority of one, truth is the truth."

Mahatma Gandhi.

### RE: Electrical Spring Contacts Material Selection

Helepolis...

arunmrao suggested BeCu, which is a good electrical contact material... and with special tempering can have very good spring properties.

SAE AS81021 Copper-Beryllium Alloy (Copper Alloy Numbers C17500 and C17510), Strip ...
1.1 Scope
This specification covers the requirements for the acquisition of two alloys of copper-beryllium alloy strip, having higher
electrical conductivity than copper-beryllium alloy strip normally used (see 6.1). All sizes of strip are covered by this
specification.
1.2 Tempers
Copper alloy numbers C17500 and C17510 strip shall be furnished flat or coiled in the following tempers, as specified in 6.2:
A - Cold rolled and solution heat treated (also designated TB00).
1/2H - Hot or cold rolled, solution heat treated, and cold rolled half-hard (also designated TD02).
H - Hot or cold rolled, solution heat treated, and cold rolled full-hard (also designated TD04).
AT - Temper A followed by precipitation hardening (also designated TF00).
1/2HT - Temper 1/2H followed by precipitation hardening (also designated TH02).
HT - Temper H followed by precipitation hardening (also designated TH04).

Regards, Wil Taylor

o Trust - But Verify!
o We believe to be true what we prefer to be true. [Unknown]
o For those who believe, no proof is required; for those who cannot believe, no proof is possible. [variation,Stuart Chase]
o Unfortunately, in science what You 'believe' is irrelevant. ["Orion", Homebuiltairplanes.com forum]

### RE: Electrical Spring Contacts Material Selection

Depending on the voltage/current involved, many spring contacts are Au plated CrCu alloys.
Cheaper and easier to work with than BeCu, but resistant to tempering.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube

### RE: Electrical Spring Contacts Material Selection

(OP)
Thanks for the replies!

Both of the suggested alloys, Be-Cu and CrCu, have similiar elastic properties as the Ti-Cu alloy?


### RE: Electrical Spring Contacts Material Selection

I used phosphor bronze for a spring contact for a mousetrap when I was a kid. It was easily available and inexpensive.

Dik

### RE: Electrical Spring Contacts Material Selection

Which properties? The springiness is only a function of the modulus, and all Cu based alloys have similar values.
How far you can deflect them is a function of yield strength.
Fatigue endurance will largely be a function of UTS.

While these various alloys will be similar they are not the same.
And neither is their resistance, so their temperatures will also be different.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube

### RE: Electrical Spring Contacts Material Selection

Ti-Cu = titanium-Copper????

Anyone else ever used Ti-Cu alloy in electrical applications? I could hardly find any common [ASTM, AMS, etc] specifications for this alloy combo... and none of those emphasized electrical contact applications.

Regards, Wil Taylor

o Trust - But Verify!
o We believe to be true what we prefer to be true. [Unknown]
o For those who believe, no proof is required; for those who cannot believe, no proof is possible. [variation,Stuart Chase]
o Unfortunately, in science what You 'believe' is irrelevant. ["Orion", Homebuiltairplanes.com forum]

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