snip
I'm no expert, so please correct me if I don't understand this
correctly. I understood that 15 Amp outlets are all rated for 20 Amps.

Tom

The ratings on the outlets are molded into the plastic bodies. All the
15A oulets in my stock are labeled '15A', period.The 20A outlets are
labeled '20A'. That seems to indicate that using the 15A's above
their capacity is not appropriate. Note that repair plugs also have
molded in ratings like outlets. HTH

Any UL-listed 15 A outlet is rated for 20 A pass through.

--
Seth Goodman

True, but generally preferred wiring practice these days is to use
pigtails for receptacles and not pass through the device itself.
Common sense would dictate that an 89 cent duplex oulet is a dubious
candidate for long term survival at the 20 amp level. Of course,
everyone can make whatever decisiuon they are comfortable with.
Cheers,

Joe