I'm looking at a round bolt bearing a "D" marking. I assume it's post-war as it has a drain-hole. Can anyone shed any light on the identity of this bolt and/or it's supposed quality?
It's not in my hands and picture's won't do much good...just visualize a blued round bolt and that's what it is. I am only considering it, if I can discover what the "D" indicates. I can see the punch-mark.