I tightened up a 1/4" lag screw that I bought from Home Depot earlier this evening. It was screwed into 1.5" fir after pre-drilling with a 1/8" pilot hole.
After it bottomed out, I turned it just a little bit more, holding a 3/8" ratchet handle close to the shaft, not out on the handle. I wasn't giving it much torque, just making sure that it was secure, when it turned to butter.
It was less torque tha I have used in the past to tighten drywall screws.
Here is the result:
I'm actually glad that this came apart on me; at least I know to get some halfway decent ones now before something failed with more catastrophic results.
Be careful what you build with the fasteners you buy from the bulk bin at Home Depot.
Jon