As I remember , it was the substitution of alum. instead of AN Steel bolts
that caused a Thorp T-18 to lose a wing panel at the EAA International
fly-in many years ago , would really want to do the numbers before I would
substitute any material on an aircraft , just the opinion of an old A/C
welder.
Phil Lohiser
Middlefield , Ohio
"Robert Loer" wrote in message
...
Plans call for wing spar to fuselage carry through attach fiitings to be
7/8x1/8 4130 steel. Advisability of using 9/16x 3/16 6061-T6 aluminum as I
have it on hand.

Your thoughts please. I have plans for another ship which uses the
6061-T6.

Thanks