glider4

Well Known Member
Ok, so I'm getting the "hardware bolts" ready for the wing mating and alignment process later this week. I go down to the local Ace Hardware store and pick up eight of their 7/16x6" Grade 5 soft steel bolts. Take them home and start putting them in the drill press to sand down any rough edges before cutting off the threads.

Wait a minute! Two of the eight bolts are bent! I mean the bolt shaft is really bent! I thought about letting them sit in a Viagra solution overnight to see it that would straighten them up but, since I was in a hurry, I just went down to Ace to exchange the bad boys.

In taking a close look at Ace's drawer of 7/16 inch bolts, about one in four was bent. The bends in the shafts were clearly visible to the eye if you looked for it. In addition to the Grade 5 marking, these bolts are marked "TY". And while they were nice and soft for cutting the threads off and grinding down to a round point, I wouldn't recommend them.
 
Believe it or not!

Almost all bolts start as coiled wire.
Some higher quality start from precision rod.

Knowing this, do not assume a bolt is straight, check it wit at least a good 6" rule, or on a truly flat surface and feeler gauges for critical applications.
 
Straight bolts

Yes, straight wing spar bolts are important even if they are just for temporary use! You would want to mar the spar or center section holes by trying to pound a bent bolt through them. The bolts marked TY on the head turn out to be counterfeit Class 5 bolts. These bolts do meet Class 5.2 specs but are useless for our purposes if they are not exactly straight. Be careful if you see TY marked on any bolt head.

Albert Thomas
N880AT RV-8A
200 hours or so to go!
 
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I ground down Class 8 bolts to use in setting my wings up for the first couple of times. A bench grinder will make fast work of the threads, even on an "8"...


Lee...
 
I use a set of giant nails for setup bolts. Don't remember what penny size they are, but they're about 10 inches long and just the right diameter. I checked them with a Micrometer & buffed them on the scotch wheel. They slide in/out nice, have a bullet nose and a head for driving/pulling.
 
Just out of curiosity,

Has there ever been an RV wing failure where scoring or maring of the main spar bolt holes was suspect