EMT Conduit Fittings: Complete Sizing & Selection Guide for Electricians (2026)
Mar 21, 2026
EMT (Electrical Metallic Tubing) is the most widely installed raceway in commercial and residential construction. Choosing the correct fittings is critical for code compliance, conductor protection, and long-term system integrity. This guide covers every EMT fitting type with sizing tables, NEC references, and installation best practices.
EMT Trade Sizes
| Trade Size | OD (inches) | ID (inches) | Max #12 THHN | Max #10 THHN |
|---|---|---|---|---|
| 1/2" | 0.706 | 0.622 | 12 | 8 |
| 3/4" | 0.922 | 0.824 | 22 | 15 |
| 1" | 1.163 | 1.049 | 35 | 24 |
| 1-1/4" | 1.510 | 1.380 | 61 | 41 |
| 1-1/2" | 1.740 | 1.610 | 84 | 57 |
| 2" | 2.197 | 2.067 | 138 | 94 |
Conductor fill is based on NEC Chapter 9, Table 1 (40% fill for 3+ conductors) and Table 5 for THHN cross-sectional areas.
Connector Types
Set screw connectors use a tightened screw to grip the EMT. Fastest to install. Suitable for dry indoor locations where the conduit is not subject to movement or vibration. Most common for commercial interiors.
Compression connectors use a threaded ring that compresses onto the EMT when tightened. Creates a concrete-tight and rain-tight connection when properly installed. Required for outdoor, wet, or damp locations per NEC 358.42.
Coupling Types
Standard couplings join two lengths of EMT in a straight run. Available in set screw and compression. Three-piece couplings (split couplings) allow joining where neither pipe can be rotated, such as repairs or additions to existing runs.
Support Requirements (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.
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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