# US PVC device boxes (Carlon, Allied Moulded): size, cubic inches, device screw spacing

> What are the dimensions and device screw spacing of a US single gang, two gang or old work electrical box?

- Category: Home & kitchen › Household
- Kind: Standard part
- Basis: Maker catalog data (ABB Carlon, Allied Moulded) and Arrow Hart wallplate catalog; only printed numbers
- Page: https://xemstudio.com/objects/device-boxes-us/ · JSON: https://xemstudio.com/api/geometry?object=device-boxes-us · Plain text: https://xemstudio.com/objects/device-boxes-us/sheet.txt
- License: dimension sheet CC BY 4.0 (Xem Studio); files CC BY 4.0 or their publisher's license
- Use in every chat: add https://xemstudio.com/mcp as a connector (https://xemstudio.com/use-with-ai/)

## Overall (mm)

| length | width | height |
|---|---|---|
| 108.7 | 25.4 | 2.0 |

**Exact dimensions.** True size, with no printing tolerance added.

## Notes

- US nonmetallic (PVC / fibreglass) device boxes, new work and old work: the sizes the makers print, the cubic-inch capacity as marked on the box, and the one position that every device box shares: the device mounting screws, 3-9/32 in apart.
- Sizes are length x width x depth as the maker's catalog data prints them. The data does not say whether an old work box length includes its ears or swing clamps, and two-gang boxes are listed with the long side in different columns, so measure your own box before you cut a wall or print a spacer.
- No drywall cutout is published as a number. Allied says to use its template (1/16 in clearance round the box) or to trace the box; Xem does not guess a cutout from the listed outline.
- The three template files carry what is printed: #6-32 device screw holes (0.138 in major diameter) 3-9/32 in apart at a 46.0 mm gang pitch. They are a design aid for a spacer, extender or smart-switch adapter plate, not a box: box interior, wall thickness and radii are not printed.
- Box fill: the cubic inches are as marked by the maker (NEC 314.16 sets the fill rules; this page does not restate them).

## Sizes

| parameter | value |
|---|---|
| Carlon B114R-UPC old work, 1-gang | 14 cu in; 4-1/8 x 2-1/4 x 2-3/4 in (L x W x D) |
| Carlon B120R old work, 1-gang | 20 cu in; 4-1/8 x 2-15/16 x 3-5/8 in |
| Carlon B225R-UPC old work, 2-gang | 25 cu in; 3-15/16 x 3-1/8 x 2-3/4 in |
| Carlon BH234R old work, 2-gang | 34 cu in; 4.3 x 4.36 x 3.59 in |
| Carlon B355R old work, 3-gang | 55 cu in; 5.72 x 2.79 x 3.69 in |
| Carlon B232BR new work, 2-gang | 32 cu in; 3-3/4 x 4 x 3 in |
| Allied Moulded 9312-E series old work, 2-gang | 28.0 cu in; depth 2-3/4, width 4-1/8, height 3-1/4 in |
| Allied Moulded 9329-EW series old work, 2-gang | 32.5 cu in; depth 3-1/4, width 4-1/8, height 3-1/4 in |
| Allied Moulded 9363-EWK old work, 1-gang | 16 cu in; 2-3/8 x 3-1/4 x 2-7/8 in (width x height x depth) |
| device mounting screws (all gangs) | 3-9/32 in (83.3 mm) apart, one pair per device; #6-32 machine screws |
| gang pitch (device centre to centre) | 46.0 mm (1.81 in), from the wall plate catalog |
| Allied old work cutout rule | template 1TP (1-gang) or 2TP (2-gang) leaves 1/16 in clearance round the box; or trace the box, stopping at the ears |
| Allied old work ear screws | two #8 sheet metal screws, at least 3/4 in long, one at each end of the box |
| wall thickness, radii, ear and clamp positions, cutout sizes | not printed as numbers: not modelled |

## Where the files are

- ABB (Carlon): [B120R 1-gang old work box, catalog data (4-1/8 x 2-15/16 x 3-5/8 in, 20 cu in)](https://empower.abb.com/ecatalog/ec/EN_NA/p/B120R) — web — Publisher's page; dimensions are facts
- G.T. Sanders (ABB Carlon data): [B114R-UPC old work box (14 cu in, 4-1/8 x 2-1/4 x 2-3/4 in)](https://www.gtsanders.com/Product/B114R) — web — Publisher's page; dimensions are facts
- Stoneway Electric (ABB Carlon data): [B225R-UPC old work box (25 cu in, 3-15/16 x 3-1/8 x 2-3/4 in)](https://www.stoneway.com/product/96915/Shared.ContactForPricing.ContactLink) — web — Publisher's page; dimensions are facts
- Stoneway Electric (ABB Carlon data): [BH234R old work box (34 cu in, 4.3 x 4.36 x 3.59 in)](https://www.stoneway.com/product/1440/Shared.ContactForPricing.ContactLink) — web — Publisher's page; dimensions are facts
- Crescent Electric (ABB Carlon data): [B355R 3-gang old work box (55 cu in, 5.72 x 2.79 x 3.69 in)](https://crescentelectric.com/electrical-boxes/outlet-boxes/three-gang-old-work-outlet-box-volume-55-cubic-inches-length-572-inches-width-279-inches-depth-369-inches-color-blue-material-pvc-mounting-means-mounting-ears-and-two-swing-clamps) — web — Publisher's page; dimensions are facts
- Stoneway Electric (ABB Carlon data): [B232BR new work 2-gang box (32 cu in, 3-3/4 x 4 x 3 in)](https://www.stoneway.com/product/815079/Shared.ContactForPricing.ContactLink) — web — Publisher's page; dimensions are facts
- Allied Moulded (via Elliott Electric): [Old work box catalog sheet 9312/9329 series: cubic inches, depths, cutout rule (box plus 1/16 in), screws](https://static.elliottelectric.com/Media/9329EWK-ALM) — web — Publisher's page; dimensions are facts
- Stoneway Electric (Allied Moulded data): [9363-EWK old work box (16 cu in, 2-3/8 x 3-1/4 x 2-7/8 in)](https://www.stoneway.com/ALLIED-MOULDED-PRODUCTS-9363-EWK-Allied-Moulded-9363-EWK-1-Gang-Switch-Receptacle-Outlet-Box-2-7-8-Inch-Depth-Thermoset-Fiberglass-Reinforced-Polyester-16-Cubic-Inch-Beige-Tan/p2288283) — web — Publisher's page; dimensions are facts
- Arrow Hart / Hubbell Wiring (via Elliott Electric): [Wallplate Dimensional Information, catalog pages J-2 and J-3 (gang pitch 46.0 mm, strap spacing 83.3 mm)](https://www2.elliottelectric.com/Media/68-EWD-1045-1-Other) — web — Publisher's page; dimensions are facts

## Questions

**How far apart are the screws in a US switch or outlet box?**

3-9/32 in (83.3 mm) between the two device mounting screws, #6-32.

**How big is a Carlon B120R?**

Listed as 4-1/8 x 2-15/16 x 3-5/8 in, 20 cu in.

**What size hole do I cut for an old work box?**

The makers do not print a number here: Allied leaves 1/16 in round the box and sells a template; trace your own box.

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