A large pin is something you should have three pieces in your haversack. Works in field repairs, blanket craft, and generally a bit like a clip hook. These are US Army surplus: huge and strong.
Length 13 cm (5.1"). Made of strong stainless steel.
Youtube is full of good tips to use a blanket pin, just type in something like "blanket pin bushcraft". We made some simple reference photos to show what you can readily do with a blanket and one pin. The pin goes through the weave of woolen blankets, without leaving a huge hole in it.
Real deal US Army surplus and even if used, it won't really show in an item like this.