This topic should really be split into several threads:

1) Good practices that are not _required_ by code.

2) Legal aspects of code enforcement.

3) Is a standard machine screw acceptable as the grounding screw (this thread) [Linked Image]

On 1) There are many good things that electricians in this forum will do, and will always do, even though code does not require it. These are things that inspectors are powerless to _require_. An example is the use of 'red heads' (anti-short bushings) on MC cable in MC cable fittings.

On 2) Remember that the NEC is _not_ law. The NEC itself is simply a list of recommendations and opinions, and in some sense has no more legal weight than Ryan's daughter [Linked Image] It is only when the NEC is adopted by the appropriate authority that this opinion begins to count and have weight of law. If the appropriate authority adopts a _different_ code (eg the IAEI codes), or adopts amendments, then these other opinions will have weight of law. It is entirely possible that a _green grounding screw_ is legally required in some places, but not in others.

On 3) My opinion only is that any machine screw with a sufficiently large head is sufficient. A 'small form' screw with a reduced head diameter may not be appropriate, no matter what the screw thread. Devils advocate: take a look at the head profile of screws that are specifically for grounding. There is clearly a bit of a concave section that helps pull the wire into the head. Most other screws that I see do not have this head profile.

-Jon