The Packard 56 type terminal you show is usually meant for use in a connector type application. Now known as Delphi/Packard. You see in your pic a bent up tab, that is to catch a lip inside connector to retain. If you want a ring tongue terminal that goes over a stud, use a standard insulated one and add heat shrink if you desire. If you want the uninsulated Packard 56 type ring tongue with a crimp for the wire and a crimp for the insulation, I found them at Texas Industrial Electrical Co. Other vendors are Waytekwire and Terminal Supply Co. Did not see any ring tongue Packards at those two. Keep in mind that when you say dual crimp, there are terminals that are made for two crimps on the wire. Used in the Space and in the Nuclear industries.(not what you want) Go to the above websites and search Packard or Packard 56. This is the name of the original 50's (1956) connector system used in Automotive. (Weatherpack is common now). The 56 is a .25 blade width and there are Packard 58 and 59 blade sizes (larger). I purchased the connectors and contacts from Terminal Supply Co. when I did my own wiring harness. $25 minimum order. Excellent people and products. They do require shrink sleeving. Most uninsulated ring tongue terminals are barrel type. These terminals are a bit pricey. .98 each. Now that you know the name you can search web for other suppliers. I believe you will find all the other type of terminals you mentioned at the Co.'s I gave. BTW: these are called terminals or contacts not connectors. A connector is the shell they fit into. (plugs and receptacles). There is a crimp on "disconnect" terminal. If a seller calls terminals and contacts: connectors, they are technically incorrect. I worked at a connector company, thus I am picky. I think you would say a terminal is for use without a connector and a contact is used inside a connector. The subject of the post is crimped or soldered products on the end of a wire. There are other uses for the words like battery "terminal" and switch "contact". TMI.
