Thomas & Betts 1-1/4 Inch Malleable Iron Erickson Conduit Coupling
Professional Conduit Connection Solution
The Thomas & Betts 1-1/4 Inch Malleable Iron Erickson Conduit Coupling delivers reliable conduit connection performance for electrical installations. This professional-grade coupling features durable malleable iron construction with precise 1-1/4 inch sizing and 1-13/16 inch depth for secure conduit joining applications.
Professional Features & Benefits
- 1-1/4 Inch Size: Provides precise fit for standard conduit connections ensuring proper alignment and secure installation.
- Malleable Iron Construction: Delivers exceptional durability and corrosion resistance for long-lasting performance in demanding electrical environments.
- 1-13/16 Inch Depth: Offers optimal engagement length for secure conduit connection and reliable mechanical strength.
- Erickson Design: Features proven coupling configuration for efficient installation and dependable conduit system integrity.
- Professional Grade: Manufactured to electrical industry standards for consistent performance in commercial and industrial applications.
Technical Specifications
- Department: Electrical
- Material: Malleable Iron
- Number Of Batteries: 0
- Product Group: Conduit & Fittings
- Product Net Depth Length: 1-13/16 in
- Product Subgroup: Couplings
- Product Type: Conduit Coupling
Professional Applications
- Commercial Electrical Installations
- Industrial Conduit Systems
- Residential Electrical Projects
- Maintenance and Repair Operations
- New Construction Wiring
- Electrical Panel Connections
Why Choose Thomas & Betts Quality?
Thomas & Betts delivers proven reliability through precision malleable iron construction and professional-grade manufacturing standards. This coupling provides the durability and performance electrical professionals trust for critical conduit connection applications.
Manufacturer Resources
Product Specs
- Product Subgroup:
- Conduit Fittings
- Product Type:
- Conduit Coupling
- Product Group:
- Conduit & Raceway
- Department:
- Electrical
- Product Material:
- Malleable Iron
- Number Of Batteries:
- 0
Thomas & Betts 678 – Frequently Asked Questions
1) What sizes does the Thomas & Betts Erickson conduit coupling come in, and which part number is which?
Two trade sizes. The 1-1/4 inch coupling is part number 678, and the 2-1/2 inch is part number 681. Order by the trade size of the rigid conduit you are joining, not by the OD of the pipe.
2) Why use an Erickson coupling instead of a standard threaded rigid conduit coupling?
A standard coupling makes you turn one of the conduits to thread it on, which means you need a free end or you have to cut the run. The Erickson (three-piece union) coupling joins two fixed lengths of threaded rigid conduit that cannot be rotated, so it is the fitting for tying into an existing run, repairing a damaged section, or closing a gap between two anchored stub-ups. If both conduits are free to spin, a plain coupling is the cheaper and simpler choice.
3) Will an Erickson coupling work on EMT or PVC conduit?
No. This is a threaded fitting for rigid metal conduit with cut male threads on both ends. EMT uses setscrew or compression couplings and has no threads, and PVC is solvent welded, so neither will engage. For EMT you need an EMT-specific coupling instead.
4) What is the Thomas & Betts Erickson coupling made of, and will it hold up in a damp industrial area?
Malleable iron. That gives it the mechanical strength to take the pull and bending load of a rigid conduit run, and it is the standard body material for threaded rigid fittings in commercial and industrial work. For direct burial or concrete pour, confirm the fitting is rated concretetight for that use; the American Fittings ER concretetight rigid coupling is an electroplated zinc steel option specifically catalogued for concretetight service.
5) How much thread engagement do I need to leave when fitting a 1-1/4 inch Erickson coupling into an existing run?
On the 1-1/4 inch size (part 678), the coupling body runs 1-13/16 inches deep, so plan your cut and threading so both conduit ends sit within that span with full thread engagement on each side. Thread both ends before you bring the halves together, since the union nut is what draws the joint tight rather than turning the pipe.
6) What else do I need to order with a 2-1/2 inch Erickson coupling?
The 2-1/2 inch coupling (part 681) ships as the complete three-piece union, so nothing else is needed for the joint itself. What you do need on site is the means to field-thread the conduit ends: a 2-1/2 inch die head and thread cutting oil, plus a reamer to clear the burr. At that size a power threader is usually the practical route rather than a hand ratchet.
7) Can the American Fittings ER coupling be used in place of a Thomas & Betts Erickson coupling on an existing conduit repair?
Not always. A repair in the middle of an installed rigid run usually leaves two threaded ends that cannot be rotated, and that is the condition the Thomas & Betts Erickson couplings in 1-1/4 inch and 2-1/2 inch are designed for - the coupling pulls both ends together without turning the pipe. The American Fittings ER is a concretetight rigid coupling in electroplated zinc steel, industrial/specification grade, and like a standard coupling it depends on being threaded onto conduit. Use the ER where you can turn one length or where concretetight performance is required, and the Erickson where neither end moves.
8) Does this Erickson coupling maintain the ground path through the conduit run?
Being a malleable iron threaded fitting, it keeps metal-to-metal continuity through the joint when both ends are threaded in fully and the union is drawn tight, the same as any rigid metal coupling. Loose or partial engagement is what breaks that path, so snug the union completely.
How fast can I get the Thomas & Betts 678 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 678 come with a warranty?
Absolutely. The Thomas & Betts 678 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 678?
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