Shoulder sheet metal screws

Sure I've seen them. The weakest point in a sheet metal screw is the diameter just under the head. Any strain will tear the sheet metal. There are screws with a shoulder machined on the head so it will fit into a larger diameter hole in the sheet metal being fastened. The shoulder distributes the stress on the metal [skin] over a larger area I believe they are used in the aircraft industry mostly to fasten Al panels. I wouldn't lnow a source for them, but they are probably described in the AN military specs. Bugs

Certainly makes sense, which is partially why I want to use them. But I thought everything in aircraft was nutted or riveted. They actually use sheetmetal screws on planes??

I have found that knowing the correct name is 90% of finding anything when dealing with the droids behind the counter anywhere. Perhaps they have a name other than that you call them, perhaps they are a proprietary design.

Happy hunting!

Cheers Trevor Jones