I got a bunch of these on a used boat that I bought. They are a one inch long 3/16 diameter black plastic bolt with a 1/4 inch high head for keeping the water on the deck out of the boat and a hole drilled down the middle for the sheet.
Nice piece. Looks like a specialty item rather than a converted plastic bolt. It is not hex head, that indentation is round.
I think they are pretty popular, maybe more so up north. I assume that the thread in the glass foam deck gets cut by just using a coarse thread 3/16 bolt or maybe a homemade thread cutter made by hack sawing that bolt off on the thread leaving a nice little burr for good thread cutting.
Any information like where can I buy them?
Thank you,
Scott