There are Tek screws available with machine threads instead of typical sheet metal threads.

These Teks with machine threads are not prohibited for grounding use.

Here is the code that prohibits sheet metal screws.

Quote
250.8 Connection of Grounding and Bonding Equipment.
Grounding conductors and bonding jumpers shall be connected by exothermic welding, listed pressure connectors, listed clamps, or other listed means. Connection devices or fittings that depend solely on solder shall not be used. Sheet metal screws shall not be used to connect grounding conductors to enclosures.

Here is a picture of a Tek screw with true machine threads.

[Linked Image from boltland.com]

[This message has been edited by iwire (edited 04-28-2004).]

Bob Badger
Construction & Maintenance Electrician
Massachusetts