Bolts for compression struts

[Dalton]

So I'm building up a new set of wings, and looking for some guidance on the bolt torque/ tightness on the bolts that hold the compression struts, Most have a AN970-4 washer under the head to spread the load out I assume, any thoughts?

[astjp2]

Snug or you will crush the spar...on a wood spar

[Hank Jarrett]

DON'T CRUSH THE WOOD!!!!! The bolts are really mostly in sheer and torque would be fine just tight enough to not rotate by hand. Where most damage is done is torquing down the aileron hinge bolts. I have seen WAY too many spars crushed in and people just seem to keep torquing the bolts trying to get them tight. Also NEVER tighten the wing to fuselage attach bolts tight! They are acting as PINS! If you tighten them you squeeze the lugs together which could cause cracking. I can put a socket and extension on my attach bolts and turn them by hand

[Robert Lees]

So I'm building up a new set of wings, and looking for some guidance on the bolt torque/ tightness on the bolts that hold the compression struts, Most have a AN970-4 washer under the head to spread the load out I assume, any thoughts?

Further to above responses: If you imagine that the compression struts are there simply to keep the spars apart (which they are), you can see that any bolts used are just to locate them in place....so use the lowest torque to just snug them up. A bit more than finger-tight; but not much more.

The Taylorcraft (and Cub and other) wings are fundamentally modified warren truss structures in planform. The same principle is used in a zillion bridges.

[Dalton]

Thanks to all, for the info. It is kinda what I was thinking as well, just needed some re-enforcing