>> No question you normally want to use fittings of matching metals.
>> However, there has been some discussion about very small aluminum
>> fittings (such as -3) not having much reserve strength (compared to
>> larger aluminum fittings and of course steel fittings).
>>

For general info group, I have used the -3 aluminum fittings and found them more than strong enough. A getoff that broke the caliper on a guard rail didn't fail the fitting. While that isn't total surity it does show that the fittings are tough. I used the Earl's fittings then. I wouldn't hesitate to use them on the aircraft.

 

Bill Jepson