The 20 Amp Extension Cord Mystery

We have a great line of extension cords intended for heavy duty use.  They use 12 gauge cable which gives them a 20 amp capacity, but we can’t really call them 20 amp cables because of the connectors that we use.

This has led to more than a little confusion among our customers.

Here’s why.

If you are familiar with standard wall outlets, you are probably aware that there are two different versions of outlets that look almost identical.

The standard 15 amp duplex receptacle (wall outlet) has openings for two parallel blades and a semi-circular ground prong.  This has been standard for almost 50 years.


An almost identical version of this outlet has an additional slot set at a right angle as part of the parallel blade opening on one side.


If the outlet has this additional right angle slot, it is intended not just 15 amp service, but 20 amp service as well.

A true 20 amp connector (male) on an extension cord will have, not two parallel blades, but rather two blades set at right angles to each other.  Otherwise they are identical.  Same size connector body, same size blades, same everything else.

15 Amp(Nema 5-15)15_amp.jpeg

20 Amp (Nema 5-20) 20_amp.jpeg

If we sold our “20 amp” extension cords with a  20 amp rated connector, they it would only plug into the version of the wall outlet that is designed to accomodate both types of blades.

20 Amp Wall Outlet(Nema 5-20)20_amp_outlet.jpeg

While we are confident that the product we sell is designed to handle a true 20 amp load, in order to truly rate an extension cord as being “20 amps” it must have one of its connector blades at right angles to the other.

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