This is a tricky question with no universally agreed-upon answer. Here's a breakdown to help you determine if EMT one-hole straps are considered "fittings" in the context of your argument about tie wire

Arguments for EMT One-Hole Straps Being Fittings:
NEC Definition (Article 100)

The National Electrical Code (NEC) defines "fittings" very broadly: "Fittings. An accessory such as a locknut, bushing, or other part of a wiring system that is intended primarily to perform a mechanical rather than an electrical function."

EMT straps are accessories. Their primary function is mechanical (supporting the EMT). Therefore, under this broad definition, they could be considered fittings.

Common Usage in the Electrical Trade

Many electricians and inspectors refer to straps, couplings, connectors, and other mechanical components as "fittings."

Purpose and Function

They are required to install the EMT in an approved manner, and they contribute to the overall system's functionality and safety.

UL Listings

Many EMT straps are UL listed, indicating they meet specific standards for their intended use. While not all fittings are UL listed, the presence of a UL listing can support the argument that they are more than just simple fasteners.

Arguments Against EMT One-Hole Straps Being Fittings



Hierarchy of System Components

In the electrical world, "fittings" often implies components that connect conduit sections or boxes, providing mechanical and sometimes electrical connections. Straps are primarily for support, not connection.

Simplicity of Design

Straps are typically very simple, single-purpose components compared to more complex fittings like connectors, couplings, or boxes.

Focus on Proper Support

The primary concern regarding EMT installations is ensuring proper support at intervals specified in the NEC. The type of strap is less critical than the spacing and securement.

Tie Wire is Still a Better Choice

Regardless of whether or not you call the straps "fittings", the tie wire is still a bad idea. It isn't rated to secure the conduit, could damage the wires and conduit and is generally against electrical code.

Your Argument About Tie Wire

The core of your debate is likely the permissibility of using tie wire to secure the EMT within the walls. Regardless of whether one-hole straps are "fittings," here's why tie wire is generally not acceptable:

NEC 300.11(A) Securely Fastened

Wiring methods must be securely fastened. Tie wire is unlikely to provide the necessary securement to prevent movement and strain on the conductors.

NEC 300.4 Protection Against Physical Damage

Wiring methods must be protected from physical damage. Tie wire offers virtually no protection against nails, screws, or other objects that could penetrate the wall.

Not Listed or Approved

Tie wire is not typically listed or approved for securing electrical conduit. Approved methods include listed straps, clamps, or other hardware specifically designed for that purpose.

Potential for Damage

Tie wire can be sharp and can potentially damage the EMT or the conductors inside.

Professional Workmanship

Good electrical practice dictates using appropriate and professional-looking methods for securing wiring. Tie wire looks unprofessional and suggests a lack of care.

Conclusion

While the definition of "fitting" is broad enough to potentially include EMT one-hole straps, the more important point is that tie wire is almost certainly an unacceptable method for securing EMT within walls. Focus your argument on the code requirements for securement, protection from damage, and the use of listed/approved materials.

Recommendation


Consult Local Codes and Inspectors

The ultimate authority on what is acceptable is your local electrical inspector. Consult with them to get a definitive ruling.2.

Focus on Code Compliance

Refer to the NEC requirements for the proper support and protection of EMT conduit.3.

Use Listed and Approved Materials

Always use electrical components that are listed by a recognized testing laboratory (e.g., UL) and approved for their intended use.4.

Advocate for Best Practices: Even if something isn't explicitly prohibited, advocate for the best and safest electrical practices. Using appropriate straps and hardware is always the better option.Good luck! Flag for review