Name that Fitting

[iadr]

Well, crush washers are not "only" for banjo fittings (used all over divider blocks, ABS pumps etc on the late model stuff, and on my antique British calipers with steel fittings very much like you show), but that's interesting & useful that the flare contact method is a known good solution. It's a fairly much steeper contacter than the bubble flare was.
Works because the fitting it a more rigid material and can handle a "single line" of contact, I guess.