i purchased an electrical appliance that has electrical specs as
follows:

single phase
240 volt
11,500 watts
(47.9amps)

it requires that the user install the power cord, i.e., it did not
come with a power cord. i will be purchasing #6 AWG for the supply
connection but am not sure which plug to buy - a NEMA 6-50 (250v 2
pole 3 wire) or a NEMA 10-50 (125v/250v 3 pole 3 wire). both are
rated for for 250 volts and 50 amps.

the big difference is price. the 6-50 plug costs (on average) about
$50 with the receptacle costing close to the same. the 10-50 plug can
be purchased for about $15 with the receptacle costing even less.

can i use the 10-50 plug and receptacle?