[quickthrowman]

Fully secured and tightened isn’t good enough. Per code, you need to use a torque screwdriver (or other approved means) to tighten the terminal screws to the torque value listed in the wiring device instructions.

> NEC 110.14 (D)

Tightening torque values for terminal connections shall be as indicated on equipment or in installation instructions provided by the manufacturer. An approved means shall be used to achieve the indicated torque value.

[Kirby64]

I can assure you this often has nothing to do with torque. The Leviton outlet lists a torque of 40 inch pounds. You can hand tighten much tighter than that relatively easy with a reasonable screw driver.

There’s some instances of undertorqued outlets, sure, but that isn’t the predominant factor here. The crap outlets are the issue.

[quickthrowman]

True, you can easily hand tighten to 40 inch pounds.

After looking at some more evidence, I agree that it’s probably just a poorly designed receptacle, probably on par with a residential 5-15R which are made to a much lower standard than a comparable commercial 5-15R.

It looks like Leviton may have discontinued the receptacle that lots of people had melt on them so that probably is the case.

[Kirby64]

The 279 outlet is just replaced by the 279-s00. I don’t think there’s much meaningful difference for Leviton outlets. It’s just similar to residential vs commercial ad you state.