Thank you for that opening, [USER]JD[/USER]. I've been pondering this for a while now. Time to do the maths with my new Vernier Calipers.
Let's compare the conductive surface area of the two hot contacts of each connector.
The male blade of a NEMA 5-15 is 0.62" long by 0.24" wide (x 0.060" thick; we'll use that later), giving 0.298 sq.in. The pin of a 20A 2P&G is 0.62" long by 0.24" in diameter, yielding a surface area of 0.467 in[SUP]2[/SUP]. Thus the pin connector's pin has 57% MORE surface area than the blade.
Of course, neither female makes full contact with the male's surface. The Edison loses again, as the female makes even less available contact than the pin connector. If you've ever seen inside a 5-15 female, it's surprising how small the "wipers" are. Twist-lock s aren't much, if any, better.
As for volume, the exposed blade contains 0.002 cu.in. The pin is 0.028 in[SUP]3[/SUP]. If I've done the math correctly, the pin contains 13 times more material (brass) than the blade.
To look at the whole thing another way, compare the 20A pin connector's pins with those from a rated/listed 60A pin and sleeve connector. The 60A's aren't that much bigger! I contend that, were it not for the termination methods and wire size limitations, the 2P&G-20 could easily safely carry many more amperes than 20. Certainly can't same the same for a NEMA 5-15, 5-20, Turn-Lock, PowerCON, or IEC 60320.
/end diatribe
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