02-02-2022, 08:30 PM
Yes, they are a screw, with a fairly coarse thread...the only thing I can equate them to today is they're similar to the screws used on metal building siding. Philco used those right from the beginning of when they started manufacturing radios, and continued to use them until the late 30s. Not sure why...most manufacturers were using bolts/screws with standard threads.