Thomas & Betts Steel City General Product Line Information

Overview

Steel City® Metallic Boxes and Covers

Steel City® is the industry-leading product line of metallic switch and
outlet boxes used in electrical construction. Since 1904, Steel City

Metallic Boxes

®

Boxes & Covers — Steel City

products have symbolized the highest quality standards in manufacturing
and innovative design, with one of the most complete offerings available.

Steel City
being the first box offering to standardize combination slotted/phillips
screws on all boxes. Thomas & Betts is also recognized as a leader
in design innovation, as in our new metal stud bracket.

Thomas & Betts continues to listen to contractors and responds
to their ever-changing needs. Contact a T&B distributor nearest
you to select the right Steel City

Advantages of Steel City® Boxes and Covers

Notched Ears on
Switch Boxes

• Steel City® Switch Boxes feature

a longer ear and a special notch.
This provides clearance for the
screws that are used to attach
wall plates to GFCI or rocker-type
light switches

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®

products are known for their simple improve ments, such as

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product for your requirements.

Raised Ground Screw
Bump in 4" Square,
411⁄16" and Utility Boxes

• Quicker surface mounting by

eliminating the need to remove
the portion of the screw that
threads through the back of
the box

A-2

MS Bracket Boxes

• Mounts without the use of screws

• Mounts to the open or closed side

of the stud

• Works on stud depths up to 4"

Eccentric Knockouts
on Square Boxes

• Provide better contact with

conduit fitting and locknut to
the box, improve grounding path,
stronger than 3⁄4" knockout

• Available in all four standard-size

square boxes

• Improved 3⁄4" knockout position on square boxes

• Less labor required to install 3⁄4" conduit to box

United States

Tel: [phone]

800.816.7809
Fax: [phone]

• Allows for improved repositioning

of grounding conductor

• Ground bump standard in 21⁄8" boxes

1

• Ground bump optional in 1

⁄2" boxes

Pre-Installed Screws
are Packaged in
Raised Position

• Eliminates extra step of having

to back out the screw during
cover installation

Steel City® switch and outlet boxes are protected from rust and
corrosion by zinc-galvanizing. All clamps and other component parts
are electrogalvanized separately, before assembly in the box, to ensure
corrosion protection of every surface. Steel City
requirements of Underwriters Laboratories, Inc. and Federal Specifications.

Technical Services

Tel: [phone]

www.tnb.com

®

galvanized finish meets the

Overview

Guide to Steel City® Knockouts, Pryouts, Ears, Brackets and Clamps

Boxes & Covers — Steel City

Knockouts and Pryouts

Steel City® conduit KOs have standard trade size dimensions. KOs are uniform and true
for attachment of cable or conduit connectors. Pryouts for cable entrance are slotted
— a twist with a screwdriver removes them. KOs and Pryouts are precision stamped
to permit easy removal, but remain sufficiently strong and sturdy when not removed.

Outlet Box Ears

Mounting ears support the box independent of the electrical system
attachments. Switch boxes have a fixed ear for old work installations.

1

Ears for plaster are set

⁄16" forward of the box face in position for old

work (modernization), except where specifically noted.

Tapped Holes for Grounding

All Steel City® boxes have a 10-32 tapped hole in the bottom
of the box for attaching separate ground wire.

Brackets

S or B Type

Mounts to face of stud. Used on

switch, handy or square boxes. 2"

long x 2

1

⁄8" wide

T Type

Positions handy box against

the face and side of stud.

51⁄2" long x 7⁄8" wide

Mounts box to side of stud with

positioning spikes.

73⁄8" long x 1" wide x 3⁄8" offset

SV Type

7

⁄8"

1

⁄2" Conduit KO

Eccentric Knockouts

Combination 1⁄2"

& 3⁄4" Knockout

Knockouts

13⁄32"

3

⁄4" Conduit KO

21

⁄32"

13⁄8"

1" Conduit KO

Pryouts

Cable Pryouts Always in Pairs

CV Type

(Outlet Boxes)

Mounts to flat

side of metal studs

or wood studs.

73⁄8" long x 1" wide

x 3⁄8" offset

®

Metallic Boxes

Mounts box offset from stud 11⁄2".
613⁄16" long x 1" wide x 11⁄2" offset

DV Type

Clamps

C-1

C-8

(Loom only)

C-10

C-5

For Armored

Cable

C-3

MS Type (For Metal Studs)

Mounts to any depth of metal stud,

21⁄2" long x 111⁄16" wide x 3⁄8" offset;

Far side support to 4" only

For Non-Metallic Sheathed Cable and Non-Metallic Tubing (Loom)

UNDERWRITERS LABORATORIES INC. and CANADIAN STANDARDS ASSOCIATION file numbers for individual items
available upon request.

Listing Information for Armored Cable Clamp — Type C-3

Armored Cable (BX) — Steel Sizes 14-2 through 10-3
Armored Cable (BX) — Aluminum Sizes 14-2 through 10-3
MC Interlocked (MCI) — Steel .449–.570 Diameter
MC Interlocked (MCI) — Aluminum .476–.606 Diameter
MC Corrugated (MCC) — Aluminum .375–.515 Diameter

“Products listed in this catalog are subject to alteration or discontinuation without prior notice.”

www.tnb.com

open or closed side.

United States

Tel: [phone]

800.816.7809
Fax: [phone]

L Type

Used to mount octagon boxes.

25⁄8" long x 35⁄8" wide x 1⁄4" offset

MCAP™— Aluminum* .370–.580
Flex Metal Conduit — Steel
Flex Metal Conduit — Aluminum
C-3 Clamp Acceptable for Grounding

* MCAP™ is a trademark of Southwire Company

Technical Services

Tel: [phone]

V Type

Mounts to flat side of stud.

73⁄8" long x 1" wide x 3⁄8" offset

1

⁄8" Trade Size

3

⁄8" Trade Size

A-3