self-tapper for bonding in aluminum post

[tommyrice]

I am considering using TEK-5 8/32 stainless screw to attach a lay in lug to an aluminum upright on an above ground pool which we will consider a permanant pool because it is capable of holding more than 42" of water.I know we need to use lugs suitable for direct burial,but am I violating the code by tapping into the 1/16" aluminum post and covering the bonding lug with dirt enen though the screw threads engage the post where they are not in contact with the soil?

 

[mcclary's electrical]

I am considering using TEK-5 8/32 stainless screw to attach a lay in lug to an aluminum upright on an above ground pool which we will consider a permanant pool because it is capable of holding more than 42" of water.I know we need to use lugs suitable for direct burial,but am I violating the code by tapping into the 1/16" aluminum post and covering the bonding lug with dirt enen though the screw threads engage the post where they are not in contact with the soil?

I would use a 10/32 tap and a real ground screw

 

[cadpoint]

I love tech 5's, In my opinion this is not a application for that screw. I don't understand why you wouldn't drill a hole and use a SS nut, bolt and washer.

I frankly equate it to a stud screw in a box for the EGC.

 

[pete m.]

250.8 Connection of Grounding and Bonding Equipment.
(A) Permitted Methods. Grounding conductors and bonding jumpers shall be connected by one of the following means:
(1) Listed pressure connectors
(2) Terminal bars
(3) Pressure connectors listed as grounding and bonding equipment
(4) Exothermic welding process
(5) Machine screw-type fasteners that engage not less than two threads or are secured with a nut
(6) Thread-forming machine screws that engage not less than two threads in the enclosure
(7) Connections that are part of a listed assembly
(8) Other listed means


Based on the 2008 NEC I don't know if the use of the TEK-5 with 8-32 thread would be a violation as long as the metal of the pole was at least 1/16 of an inch thick.

Pete

 

[tommyrice]

response to using regular 10/32 grnd screw

response to using regular 10/32 grnd screw

because reg grnd screw is not stainless steel or other material suited for direct burial,I would be reluctant to use it in this scenario

 

[cadpoint]

Since I have gone out on a limb here a lot lately on my opinion(s) here, I really don't understand "(6) Thread-forming machine screws that engage not less than two threads in the enclosure"
I spent the afternoon Saturday, trying to understand exactly what that mean!

I got a great refresher as to various types of screw threads but no answer as to what the exact red phrase meant to anything in respects to screw threads!

Now I have seen both course and fine screw threads described (neither were implied as a Tech-5 screw), in the Machicst handbook, this is not a NFPA point of reference. While course and fine are technically defined in other terms as to a what might describe a tech screw might be, its applicaition, is is not listed (but my book is older).

There is a property listing that states what aluminum can handle as being taped. 10 tapes per inch, but this is not a 10/32 or a 10/16 it's just 10 per inch. So that would be a wide course thread as far as I understand it.
With the 2/3rd, I'm still lost.

 

[mcclary's electrical]

because reg grnd screw is not stainless steel or other material suited for direct burial,I would be reluctant to use it in this scenario

Good point. But this is above grade. I think it would be fine. Halex and Leviton's screw are both rated for outdoors

 

[quinn77]

my 2 cents....
a tek screw is not a "thread forming machine screw" like you would find on some makes of panel and meter hubs. a thread forming machine screw for example a 10-32, would have tapered threads with a "notch" on one side of the screw to remove any material as it is being installled.

 

[quinn77]

ok...so my lack of experience with tek 5 shows:roll:....that would be a thread forming machine screw from the looks of it. the screws i mentioned in previous post are usually found in flourescent strips and lay in types as the provided ground screw.

 

[kwired]

I question if it is a good idea on 1/16 inch aluminum to have it tapped, I can see that connection failing in a short time.

 

[mcclary's electrical]

I question if it is a good idea on 1/16 inch aluminum to have it tapped, I can see that connection failing in a short time.

the threads of a tek screw are so course, it would have to be 1/2" thick to get (2) full threads