I have LOTS of these to make... I need to find one of the many old track pin threads to get the exact steel, but from memory it was a chromoly type steel.
DO NOT USE STAINLESS
If you are forming the heads you will need to make a precision jig for the pin to prevent swelling at the formed end.
I am currently making rivet snaps for people at the moment, so perhaps I need to make a tool for the pin ends too
I don't like the idea of the entire track length being pinned using split pins (cotter pins to the Colonials)
I have an idea of forming a second threaded button which can be wound onto the pin once fitted with suitable compound to fix it in place.
In our small "Suffolk Syndicate" this will be my project for the builds we have ahead this year.