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Manufacturer Resources
Product Specs
- Cubic Capacity:
- 21.5 Cubic Inches
- Extension Ring:
- Y
- Knockouts:
- 4
- Number Of Outlet:
- 1
- Outer Dimensions Inches:
- 15.82x9.5x6.44
- Outer Quantity:
- 25
- Standards:
- UL E2969
- Unspsc:
- 39121320 Electrical box extension
- Weight Uom:
- 45 lbs. per 100
- Department:
- Electrical
- Product Group:
- Electrical Enclosures
- Product Subgroup:
- Boxes
- Product Type:
- Electrical box extension
- Product Size:
- 4 Inches Diameter x 2-1/8 Inches Depth
- Product Details:
- Extension Rings
- Product Color:
- Silver
- Product Diameter:
- 101.6mm
- Product Material:
- Steel
Steel City 4-OD-EXT-1/2 – Frequently Asked Questions
1) Will a Steel City 4-OD-EXT-1/2 extension ring fit a standard 4 inch round octagon box?
The 4-OD-EXT-1/2 is a 4 inch diameter round extension ring, 2-1/8 inches deep, so it mounts on a standard 4 inch round box using the box's existing mounting ears. Diameter is listed at 101.6mm, which is the same 4 inch round pattern.
2) How much box fill does a 4 inch extension ring add for conductor count?
It adds 21.5 cubic inches of volume. That is the number you add to the original box capacity when you are running the NEC box fill calculation, and it is the usual reason to add a ring instead of replacing the box when the existing enclosure is overcrowded.
3) Can I bring additional conduit into this extension ring?
Yes. The 4-OD-EXT-1/2 steel extension ring has 4 knockouts, sized for 1/2 inch trade conduit or connectors, so you can land a new run at the ring rather than reopening the original box.
4) Is this extension ring listed?
It carries UL file E2969. The body is steel with a silver finish, which is the standard galvanized-look finish for concealed and exposed steel box work.
5) When should I use an extension ring instead of replacing the electrical box?
Use a ring like the 4-OD-EXT-1/2 when the existing box is set too deep after new drywall, tile, or panelling goes over the wall, or when you need more volume for added conductors. It adds 21.5 cubic inches and 2-1/8 inches of depth without cutting the wall open or pulling the box out of the framing. If the box itself is damaged or the mounting is loose, replace the box instead.
6) How many device openings does the 4-OD-EXT-1/2 ring provide?
One outlet position. It is a single-gang-equivalent round ring, so it extends a single device or fixture opening out to the new finished surface, not a two-gang layout.
7) Does the Steel City 4-OD-EXT-1/2 come in a case quantity?
It ships in cartons of 25. Carton weight works out to 45 lbs per 100 pieces, which matters if you are ordering pallet quantities for a multi-unit rewire.
How fast can I get the Steel City 4-OD-EXT-1/2 delivered?
Most orders ship the same day from our distribution partners, with quick delivery throughout the
continental
U.S.
Need it urgently? Contact Us for expedited shipping options.
Can I return it if it doesn’t work for me?
Yes—ZenSupply offers a hassle-free return policy. If the product isn’t the right fit,
reach out to our support team for a return authorization or setup a return by following our return instructions.
Does the Steel City 4-OD-EXT-1/2 come with a warranty?
Absolutely. The Steel City 4-OD-EXT-1/2 is backed by a manufacturer’s warranty.
For full warranty terms, check the product documentation or Contact Us.
How do I get technical support or installation help for the Steel City 4-OD-EXT-1/2?
You can call, text, or email our expert support team for fast answers. We’re here to help with
product
selection,
installation tips, and troubleshooting. Contact Us
Why buy the Steel City 4-OD-EXT-1/2 from ZenSupply?
ZenSupply makes it easy to get the commercial door hardware you need—fast shipping, expert support,
and
rewards on
every order.
Our team is always ready to help you choose the right product for your project.