Should I pigtail metal box with 8-2 cable?

[katit]

So, the question is in title. Those 2-gang metal boxes installed for future outlets or direct-wired appliances. How should I pigtail them? It makes sense to do in 8ga, but wires is not single thread, and 3 of them in a twist connector? Also, probably too big for a screw?

 

[rmanrman]

So, the question is in title. Those 2-gang metal boxes installed for future outlets or direct-wired appliances. How should I pigtail them? It makes sense to do in 8ga, but wires is not single thread, and 3 of them in a twist connector? Also, probably too big for a screw?

If it’s a metal box then yes it must be bonded to the ground conductor
Also you can connect the three conductors in a connector called a “bug” you use a wrench to clamp down the wires

 

[mm08822]

Probably only need #10 Copper. What size breaker feeds this box?
Add a ring terminal on the end of the #10 and attach to metal box with a dedicated green ground screw.

Use a split-bolt connector (bug) slid down ~4" onto the ground conductor from the cable and connect the #10 to it.
Form the wires in the box so they lay nicely and not fighting you.

 

[katit]

Probably only need #10 Copper. What size breaker feeds this box?
Add a ring terminal on the end of the #10 and attach to metal box with a dedicated green ground screw.

Use a split-bolt connector (bug) slid down ~4" onto the ground conductor from the cable and connect the #10 to it.
Form the wires in the box so they lay nicely and not fighting you.

It's 40A breakers. I just realized that ground wire on my 8-2 is already #10

Is this "bug" readily available in Home Depot? Also, is there "special" ring terminals to use? I assume they can be just crimped on?
And I need to get some solid #10 for ground?

 

[mm08822]

It's 40A breakers. I just realized that ground wire on my 8-2 is already #10

Is this "bug" readily available in Home Depot?

Yes.

Also, is there "special" ring terminals to use? I assume they can be just crimped on?

A #12-10 ring terminal can be crimped on.

And I need to get some solid #10 for ground?

1 foot. green or bare.