250.8(5), (6) engage not less than 2 threads

[PCBelarge]

I did some research on this topic with manufacturers. I am curious how others are understanding that they are actually catching 2 threads. " I have done it .... way forever" or other non factual means are unacceptable.

 

[letgomywago]

I did some research on this topic with manufacturers. I am curious how others are understanding that they are actually catching 2 threads. " I have done it .... way forever" or other non factual means are unacceptable.

Do the math you need so much material thickness to do 2 threads at 32 per in. If it's more than 1/16 thick then a tap is all that's needed. If that's not thick enough then nut and bolt are acceptable no matter the thickness.

 

[petersonra]

The are some boxes that are punched out where the area around the hole is thickened up by using the material removed from the hole to get to 1/16 inch. It's why you are generally required to use fone thread screws.