sheet metal screw versus machined screw. number of threads

[grasfulls]

CREE engines come with a bonding jumper attached via a machine screw to the top of the engine. The installation instructions state to loosen one of the sheetmetal screws at the bootom of the housing and use this to attach the bonding jumper. Does not proper bonding require a machine screw and a minimum number of threads? The side of the CREE can is rather thin aluminum and thos screws strip REAL easy.

 

[K8MHZ]

CREE engines come with a bonding jumper attached via a machine screw to the top of the engine. The installation instructions state to loosen one of the sheetmetal screws at the bootom of the housing and use this to attach the bonding jumper. Does not proper bonding require a machine screw and a minimum number of threads? The side of the CREE can is rather thin aluminum and thos screws strip REAL easy.

I can't find it in the book, but the minimum is two full threads.

 

[grasfulls]

Osha rule for grounding

Osha rule for grounding

I can't find it in the book, but the minimum is two full threads.

Thanks...
I wonder how manufacturers ge UL or other listings when they violate codes so easily.

I like the OSHA rule you use as a signature. Does that mean ground it again? I am going to go look that one up.

 

[K8MHZ]

Thanks...
I wonder how manufacturers ge UL or other listings when they violate codes so easily.

I like the OSHA rule you use as a signature. Does that mean ground it again? I am going to go look that one up.

I found the rule. It's 250.8 (A).

Beside machine screw type fasteners that engage not less than two threads or are secured with a nut, connections that are part of a listed assembly are also allowed.

As for my OSHA quote, well, it says what it says. :lol:

 

[grasfulls]

Need those threads! (for OSHA)

Need those threads! (for OSHA)

I found the rule. It's 250.8 (A).

Beside machine screw type fasteners that engage not less than two threads or are secured with a nut, connections that are part of a listed assembly are also allowed.

As for my OSHA quote, well, it says what it says. :lol:

AWESOME!! thanks... The OSHA code speaks volumes for OSHA enforcement. Theoretically one could put ground upon ground indefinitely to comply...