This is what caused the one accident I am aware of. You absolutely don?t want to use a cheap or unknown grade bolt. The accident also involved how the guy used the jacks. He did not raise the tail and put a side load on his cheap bolts, which snapped. There is a conversation about this accident somewhere in the archives.

I always insure my bolts are perpendicular to the jack, or as close as I can get them. Probably overkill for a grade5 or 8 bolt, but I don?t want to put them in shear regardless.

Another consideration is do not use a bolt that is too long!

Or just bolt a 1-1/8? or so 3/8 drive socket into the tie down and run the jack ram into that. No jack mod required. Been working for me and the local gang for over a decade. I put a UHMW tape covered fender washer between the socket and skin to protect the paint.

Wow Steve, Those look really nice! Thanks for the link.

Angle the Jack
 

For best results and safety, you need to angle the jack outward at the base. The angle at the jackpoint gets surprisingly large and scary looking as you raise the wing high enough to get the tire off the ground.

An Allen Head Bolt
 

I use a 1? stainless allen head bolt with a large area washer under the head. I snug it to the bottom of the wing and lift away with my short wing jack. (got lucky on a pair of jacks intended for low wing Pipers). Stainless just because it looks cool, plain steel would be just as good. I don?t use that hole for the tiedown any more after installing spring loaded retractable tiedowns in the wingtips.

Our solution.

https://photos.app.goo.gl/pKFMmQQFderDY2z47

I just bought some large steel pipe caps, drilled them in the center, and inserted a grade 8 bolt and put a washer and nut to hold it in place to capture the hydraulic ram from the jack.



Easy project at minimal cost and they have performed just fine for jacking up the airplane.

Ditto for me.

Raise the tail.
It is really important to raise the tail and reduce that angle. The one accident I am aware of used hardware store bolts and did not raise the tail putting the cheap bolts in shear. He might have been fine if he raised the tail but still use quality bolts or an engineered product.