"Ignoramus7553" wrote in message
...
I have a wooden cart on casters on which I will have a generator. Its
weight is 1,400 lbs, and the weight of the entire stucture would be
1,600 lbs. This cart may one day be winched into a trailer on
ramps.

To the front of the cart, I want to attach a lifting eye. It is a big
lifting eye with the threaded stem removed, and welded to a 1/4"
plate, which would be attached to the cart by means of four 5/16" lag
screws.

My question is, what is the optimal length of these lag screws. The
wood is regular soft wood. I assume that beyond some length, the extra
grip given by extra length is meaningless.

I have worked with lag screws extensively and I do not feel confident that
lag screws will hold consistently any heavy load if the stress is being
applied vertically. Horizontally (to the lag screw) perhaps, but not
vertically.

If the lag screws are stressed sideways, I would want at least 3 1/2" to 4"
minimum.

I would suggest some kind of threaded BIG bolts, another plate on the other
side from the eye plate, and extra nuts.

I have built platforms that needed to be winched onto a trailer or truck
before. What I did was to jrill a big hole and run a bolt throough it. I
cut out a section near the middle of the bolt. I then threaded the bolt
through a big iron ring. This was sufficent for any kind of hook or other
means of attaching the cart to the cable.