Conduit Bushings Explained: Types and What to Check Before Ordering

Last updated: August 4, 2026

TL;DR: “Conduit bushing” can describe several different products, including threaded bushings, insulated bushings, grounding bushings, reducing bushings, and products intended for specific cable systems. Before ordering, confirm the bushing’s function, raceway type, trade size, material, connection, environment, listing, and approved project requirements.

What Is a Conduit Bushing?

A conduit bushing is a fitting used at a conduit, raceway, cable, or enclosure connection. Depending on the product, it may provide a smooth surface at an entry, reduce a threaded opening, or provide another function identified by the manufacturer.

The word “bushing” is used for several products that serve different purposes. A bushing that fits physically may still be wrong for the raceway, enclosure, cable, environment, or approved design.

Common Products Described as Bushings

Standard Threaded Bushings

These bushings thread onto compatible conduit or fittings. Products are available in different trade sizes, materials, and finishes. Confirm the thread type, raceway, and intended use before ordering.

Insulated-Throat Bushings

Insulated-throat bushings include an insulating surface around the opening. The product description should identify the material, trade size, thread type, and conduit or fitting with which it is intended to be used.

Do not select an insulated bushing based solely on circuit voltage. The approved design and applicable requirements must determine whether it is needed.

Grounding or Bonding Bushings

Grounding and bonding bushings are designed with provisions for an approved bonding connection. They are different from ordinary threaded or insulated bushings.

Whether a grounding or bonding bushing is required depends on the complete system, enclosure, raceway, service conditions, approved design, and applicable requirements. That determination belongs to the qualified professional responsible for the work.

Reducing Bushings

A reducing bushing connects compatible threaded openings of different sizes. Its primary function is size reduction, so it should not be confused with a protective or grounding bushing.

Record both sizes when requesting a reducing bushing. A request for a “one-inch bushing” does not explain which side is one inch or what smaller size is required.

Anti-Short Bushings

Anti-short bushings are small inserts associated with specific armored-cable products and applications. They are not general replacements for threaded conduit bushings.

Provide the cable type, cable size, manufacturer information, and applicable project requirement when ordering.

Plastic Snap-In Bushings and Grommets

Some plastic bushings snap into compatible holes or openings rather than threading onto conduit. Confirm the panel or enclosure opening, panel thickness, cable or conductor range, material, and product listing.

What to Check Before Ordering

1. What Function Is Required?

Determine whether the approved material list calls for a standard, insulated, grounding, reducing, anti-short, or snap-in product. Do not treat these descriptions as interchangeable.

2. What Raceway or Cable Is Involved?

Identify the exact conduit, tubing, raceway, or cable type. Useful information may include:

• Rigid metal conduit
• Intermediate metal conduit
• PVC conduit
• Armored cable
• Metal-clad cable
• Panel or enclosure opening

Use the terminology shown on the approved plans, specifications, product packaging, or manufacturer documentation.

3. What Trade Size or Opening Size Is Needed?

Record the exact trade size. For reducing bushings, provide both the larger and smaller sizes. For snap-in products, include the opening diameter and panel information.

4. What Connection Is Required?

Confirm whether the product is threaded, snap-in, push-in, or intended for a specific cable or fitting. Similar-looking products may attach differently.

5. What Material or Finish Is Specified?

Available materials may include plastic, PVC, steel, malleable iron, zinc, or a combination of metal and insulating material. Match the approved specification and environmental requirements.

6. Where Will It Be Used?

Identify whether the location is:

• Indoors or outdoors
• Dry, damp, or wet
• Exposed to corrosion or coastal conditions
• Subject to vibration or physical damage
• Part of service equipment or another specialized system

The manufacturer documentation must support the intended environment. Do not assume any plastic or metal bushing is automatically suitable outdoors.

7. What Listing or Approval Is Required?

Review the product markings, approved plans, specifications, and manufacturer documentation. UL identifies outlet bushings and several related conduit-fitting categories under standards including UL 514B. See UL’s overview of conduit, tubing, and cable hardware.

8. Are You Matching Existing Equipment?

For replacement products, record:

• Manufacturer
• Catalog or part number
• Trade size
• Material and finish
• Visible markings
• Clear photographs from several angles

A photograph helps, but measurements and product markings usually provide more dependable identification.

What to Bring to the Revco Counter

Bring or send:

• Bushing type or required function
• Conduit, raceway, cable, or enclosure type
• Trade size or opening size
• Thread or connection type
• Material and finish
• Indoor or outdoor environment
• Manufacturer and part number when available
• Photos of the existing product and markings
• Approved product requirements
• Quantity and required date

Browse Revco’s conduit bushings, review additional conduit fitting categories, or bring the information to a Revco electrical supply counter.

Frequently Asked Questions

Are all conduit bushings insulated?

No. Some have an insulating throat, while others are metal, plastic, reducing, grounding, or intended for a particular cable system. Check the complete product description.

Can a plastic bushing replace a metal bushing?

Not automatically. The products may have different functions, attachment methods, listings, and permitted uses.

Is a reducing bushing the same as an insulated bushing?

No. A reducing bushing changes between compatible threaded sizes. An insulated bushing includes an insulating surface around the opening.

Does using a listed bushing guarantee code compliance?

No. The product must also be correct for the complete system, installed according to its instructions, and used in accordance with approved project and local requirements.

Can Revco identify a replacement from a photograph?

A photograph may narrow the options, but the manufacturer, part number, trade size, connection type, and application details are still important.

Final Takeaway

Before ordering a conduit bushing, identify its function, compatible raceway or cable, trade size, connection, material, environment, listing, and approved project requirement. That information is far more useful than color or appearance alone.

Disclaimer

This article provides general product-identification and ordering information. It is not electrical design, installation, grounding, bonding, engineering, code, or inspection advice. Final product selection and installation must follow approved project documents, manufacturer instructions, applicable requirements, and qualified professional guidance.

About Revco Lighting & Electrical Supply

Revco Lighting & Electrical Supply has served Long Island trade professionals since 1978. Through six Suffolk County branches, Revco helps customers source lighting and electrical products, review manufacturer information, request quotes, and coordinate pickup or eligible delivery. Visit Revco’s locations page to find a nearby branch.