EMT Conduit Fittings: Complete Sizing & Selection Guide for Electricians (2026)
Apr 03, 2026
EMT (Electrical Metallic Tubing) is the most widely installed raceway in commercial and residential construction. Choosing the correct fittings — connectors, couplings, straps, and bushings — is critical for code compliance, conductor protection, and long-term system integrity.
EMT connector types
Set-screw connectors use a tightened screw to grip the EMT. They are the fastest to install and suitable for dry indoor locations where the conduit is not subject to movement or vibration. Set-screw is the most common choice for commercial interiors.
Compression connectors use a threaded ring that compresses onto the EMT when tightened. This creates a concrete-tight and rain-tight connection when properly installed. Compression connectors are required for outdoor, wet, or damp locations per NEC 358.42.
EMT trade sizes and conductor fill
| Trade size | OD (inches) | ID (inches) | #12 THHN (40%) | #10 THHN (40%) |
|---|---|---|---|---|
| 1/2" | 0.706 | 0.622 | 9 | 5 |
| 3/4" | 0.922 | 0.824 | 16 | 10 |
| 1" | 1.163 | 1.049 | 26 | 16 |
| 1-1/4" | 1.510 | 1.380 | 46 | 28 |
| 2" | 2.197 | 2.067 | 104 | 65 |
Conductor fill is based on NEC Chapter 9, Table 1 (40% fill for 3+ conductors) and Table 5 for THHN cross-sectional areas.
NEC support and securing requirements
Per NEC 358.30, EMT must be secured within 3 feet of every box, cabinet, or fitting, and supported at intervals not exceeding 10 feet. Use one-hole or two-hole straps rated for the trade size. Beam clamps and conduit hangers are acceptable for suspended installations.
When to use insulating bushings
NEC 300.4(G) requires insulating bushings where conductors #4 AWG and larger enter a raceway. Plastic insulating bushings protect conductor insulation from the sharp edge of cut EMT. Grounding bushings with bonding lugs provide an additional equipment grounding path.
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