Thomas & Betts 4" to 3-1/...
IN STOCK (leaves warehouse same day if ordered before 3pm ET)
$1,143.15
$20.35
Thomas & Betts 1258 4 TO 3-1/2IN FEMALE REDUCER IRON

Thomas & Betts 4" to 3-1/2" Female Reducer - Malleable Iron Conduit Fitting

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Model: 1258
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In Stock (leaves warehouse same day if ordered before 3pm ET)

$1,143.15
$20.35
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Thomas & Betts 4" to 3-1/2" Female Reducer

Professional Malleable Iron Conduit Fitting for Size Transitions

The Thomas & Betts 4" to 3-1/2" Female Reducer provides reliable conduit size transitions in electrical installations. Constructed from durable malleable iron, this professional-grade fitting ensures secure connections when reducing from 4-inch to 3-1/2-inch conduit systems, delivering the trusted quality and performance expected from Thomas & Betts electrical components.

Professional Features & Benefits

  • 4" to 3-1/2" Size Reduction: Enables smooth transitions between different conduit diameters for flexible system design and installation requirements.
  • Malleable Iron Construction: Provides exceptional durability and corrosion resistance for long-lasting performance in demanding electrical environments.
  • Female Threading: Ensures secure, threaded connections that maintain system integrity and prevent loosening over time.
  • Professional Grade Design: Engineered to meet rigorous electrical industry standards for reliable conduit system performance.
  • Versatile Application: Suitable for various electrical installations requiring conduit size transitions in commercial and industrial settings.

Technical Specifications

  • Department: Electrical
  • Material: Malleable Iron
  • Number Of Batteries: 0
  • Product Group: Conduit & Fittings
  • Product Subgroup: Reducers
  • Product Type: Female Reducer

Professional Applications

  • Commercial Building Electrical Systems
  • Industrial Facility Conduit Networks
  • Institutional Electrical Installations
  • Multi-Unit Residential Properties
  • Professional Office Buildings
  • Retail and Service Establishments
  • Educational and Healthcare Facilities

Why Choose Thomas & Betts Quality?

Thomas & Betts delivers proven reliability through precision-engineered malleable iron construction that withstands the demands of professional electrical installations. This female reducer maintains the high standards of quality and durability that electrical professionals trust for critical conduit system applications.

Manufacturer Resources

Product Specs

Number Of Batteries:
0
Product Group:
Conduit & Raceway
Product Type:
Reducer
Department:
Electrical
Product Subgroup:
Conduit Fittings
Product Material:
Malleable Iron

Thomas & Betts 1258 – Frequently Asked Questions

1) What does the Thomas & Betts 1258 reducer actually do in a conduit run?
The Thomas & Betts 1258 is a female reducer that transitions a 4 inch rigid conduit connection down to 3-1/2 inch. Both ends are female threaded, so it threads onto male conduit thread on each side, letting you carry a 4 inch run into a 3-1/2 inch run (or into a 3-1/2 inch hub) without reworking the whole raceway.
2) Is the 1258 reducer threaded or set screw?
Threaded, both sides, and female. That means it mates with threaded rigid or IMC conduit ends, not with EMT. If you are working in EMT you need a set screw or compression reducing connector instead, since EMT is not threaded.
3) What is the Thomas & Betts female reducer made of, and will it hold up outdoors or in an industrial plant?
Malleable iron. It is the standard body material for threaded rigid conduit fittings in commercial and industrial work, and it is specified here for durability and corrosion resistance in demanding electrical environments. For heavy wash-down or corrosive process areas, most specs call for a PVC-coated or non-ferrous fitting rather than plain malleable iron.
4) Can I use the 1258 reducer to go from 3-1/2 inch up to 4 inch instead of down?
Yes. A reducer is a passive threaded transition, so direction of the run does not matter. Thread the 4 inch side to your 4 inch conduit or enclosure hub and the 3-1/2 inch side to the smaller conduit, whichever way the pull is going. The only thing that matters is that both connections are male threaded, because both openings on the 1258 are female.
5) What is the Thomas & Betts part number I should order for a 4 inch to 3-1/2 inch female reducer?
Order Thomas & Betts 1258. That single catalog number covers the 4 inch to 3-1/2 inch female reducer in malleable iron; there is no finish or size choice to specify with it.
6) Do I need a locknut, bushing or anything else with this reducer?
No separate hardware ships with the 1258, and none is required for a straight conduit-to-conduit transition, since it threads directly onto both conduit ends. If you are landing it on an enclosure wall rather than on conduit, that penetration still needs its own hub or locknut and bushing, which are ordered separately.
How fast can I get the Thomas & Betts 1258 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 Thomas & Betts 1258 come with a warranty?
Absolutely. The Thomas & Betts 1258 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 Thomas & Betts 1258?
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 Thomas & Betts 1258 from ZenSupply?
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