ECN Forum Forums Code Related Discussion NEC & other Code issues Are concentric or eccentric knockouts evaluated for bonding?

Just to be sure, you should read the following information very carefully, when evaluating concentric and eccentric knockouts:
http://www.ul.com/regulators/knockouts.cfm

Intresting have you seen any boxes or cabinets marked? I will be looking for them but I still probably still bond bush so not to upset an inspector who hasn't seen the marking, plus just assurance that it is bonded and be ease of mind.

Yes,

The following table summarizes the box and enclosure categories where such an evaluation is available and how to identify compliant products that can be installed according to the exception to Section 250.97.

Category Code
Product Category
Concentric and eccentric knockouts evaluated for bonding?

BGUZ
Boxes, Junction and Pull
Only when product is marked*

CYIV
Cabinets and Cutout Boxes
Only when product is marked*

QCIT
Metallic Outlet Boxes
All products comply


* Products Listed for these applications are provided with a marking, such as "Concentric (or eccentric) knockouts suitable for bonding conduits for non-service conductors."

+1 for the additional bonding.

The $8 in parts is worth more than 20 minutes proving your point to an inspector.

Just knock out the KO all the way and use reducing washers. They are UL listed for grounding. Save the cost of the bond bushings.