Quick Hits

⚡ NEC Quick Hit: Article 358 - Electrical Metallic Tubing (EMT) ⚡

 Pulling thin-wall EMT? Know your fill limits and internal dimensions before you pull the wire. Here is your quick-reference breakdown for standard trade sizes! 👇

SLIDE 2 (SMALLER TRADE SIZES) EMT Internal Dimensions & Fill Areas (1/2" to 1"):

• 1/2" Trade Size (Metric 16):

  • Total Area (100%): 0.304 in² (196 mm²)

  • Over 2 Wires (40% Fill): 0.122 in² (78 mm²)

  • Internal Diameter: 0.622 in. (15.8 mm)

• 3/4" Trade Size (Metric 21):

  • Total Area (100%): 0.533 in² (343 mm²)

  • Over 2 Wires (40% Fill): 0.213 in² (137 mm²)

  • Internal Diameter: 0.824 in. (20.9 mm)

• 1" Trade Size (Metric 27):

  • Total Area (100%): 0.864 in² (556 mm²)

  • Over 2 Wires (40% Fill): 0.346 in² (222 mm²)

SLIDE 3 (MEDIUM TO LARGE SIZES) EMT Fill & Area Reference (1-1/4" to 2"):

• 1-1/4" (Metric 35): Total Area 1.496 in² | 40% Fill: 0.598 in² | ID: 1.380 in.

• 1-1/2" (Metric 41): Total Area 2.036 in² | 40% Fill: 0.814 in² | ID: 1.610 in.

• 2" (Metric 53): Total Area 3.356 in² | 40% Fill: 1.342 in² | ID: 2.067 in.

⚠️ Note: Larger sizes like 2-1/2" up to 6" scale up fast—always verify your conductor cross-sections against these Chapter 9 tables to keep commercial runs compliant.

SLIDE 4 (WRAP-UP) 💡 Apprentice Tip: Remember your fill rules from Chapter 9 Table 1—53% for 1 wire, 31% for 2 wires, and 40% for over 2 wires.

💬 Save this post for your next commercial rough-in or exam prep! 🔗 More code breakdowns and apprentice tools at www.JoshTheSparky.com

← View Chapter 9 Home

← Back To Percent of Cross Section of Conduit for Conductors Home

← Back To Quick Hits Home