Wire Bending Standards / Strain Relief
Wire Bending Standards / Strain Relief
(OP)
Hi,
I'm looking for a standard for instituting strain relief into a wire. I've looked through the NASA workmanship standards and I can't find anything explicit. For example with sheet metal, I've heard a general rule that bend radius must be greater than 1.5 times the thickness.
What is the rule for wire?
What is the general spec for sufficient strain relief?
The situtation is a wire soldered to a pin that goes up through a fixed point in a panel. The panel flexes and so the connection between the panel and the pin must have adequate strain relief.
I'm looking for a standard for instituting strain relief into a wire. I've looked through the NASA workmanship standards and I can't find anything explicit. For example with sheet metal, I've heard a general rule that bend radius must be greater than 1.5 times the thickness.
What is the rule for wire?
What is the general spec for sufficient strain relief?
The situtation is a wire soldered to a pin that goes up through a fixed point in a panel. The panel flexes and so the connection between the panel and the pin must have adequate strain relief.





RE: Wire Bending Standards / Strain Relief
RE: Wire Bending Standards / Strain Relief
RE: Wire Bending Standards / Strain Relief
In any case, MIL-STD-454 isn't any help, "prevent undue stress."
If the flex is a LOT, then as much service slack as practical to prevent fatigue. Copper tends to work harden. Oxygen-free copper is supposedly more robust.
TTFN
FAQ731-376: Eng-Tips.com Forum Policies
RE: Wire Bending Standards / Strain Relief
RE: Wire Bending Standards / Strain Relief
As a data point, we built a flex cable with a 2" diam service loop for a rotary joint application using standard copper wiring that lasted about 100k cycles. Unfortunately, that represented only about 50 hrs of operating time. So the OFC high-ductility wiring was used in its place and the cycle lifetime was in excess of 10 million, making the system viable.
TTFN
FAQ731-376: Eng-Tips.com Forum Policies
RE: Wire Bending Standards / Strain Relief
RE: Wire Bending Standards / Strain Relief
TTFN
FAQ731-376: Eng-Tips.com Forum Policies
RE: Wire Bending Standards / Strain Relief