Full Electrical System Protection

Manufactured from mild steel, Allied’s Rigid Conduit is highly resistant to damage from impact yet ductile to facilitate bending.

The ¾” taper NPT threads (ANSI B1.20.1) are full cut and hot galvanized after cutting. Color-coded end cap thread protectors keep the threads clean, sharp and also provide instant trade size recognition. Even sizes are color-coded blue, 1/2 sizes black, and 1/4 sizes red.

  • Hot-dip galvanized for excellent corrosion resistance
  • High strength ductile steel for long life and easy bending
  • Smooth, continuous raceways for fast wire pulling
  • Kwik-Release End Cap to protect threads
  • True Color GRC special orders available
  • Listed to Safety Standard UL 6
  • Manufactured in accordance with ANSI C80.1
  • Available in trade sizes 1/2 (16) – 6 (155)


Hot-dip galvanized inside and out to provide galvanic corrosion protection. Also, top coated with a compatible organic layer to protect against white rust. The inside surface is evenly coated for wire-pulling ease, even through multiple 90° bends.

EMI Shielding

Allied Rigid Steel Conduit is very effective in reducing the effects of electromagnetic field levels for encased power distribution circuits, shielding computers and other sensitive electronic equipment from the effects of electromagnetic interference. Learn more with the GEMI (Grounding and Electro-Magnetic Interference) software analysis program.

Codes & Standards Compliance

Allied Rigid Steel Conduit is precision manufactured for dependable, long-lasting value and ultimate protection for electrical conductors. Covered by article 344 of the National Electrical Code (NEC), rigid steel conduit is highly resistant to damage from impact. It can be installed in all occupancies and locations, including Class I Division 1 hazardous locations. Rigid steel conduit is recognized as an equipment grounding conductor in Section 250.118 of the NEC. It is listed to Underwriters Laboratories Safety Standard UL 6 and is manufactured to ANSI C80.1, both of which have been adopted as Federal Specifications in lieu of WWC 581.

Installation of Rigid Metal Conduit shall be in accordance with the National Electrical Code and UL General Information card #DYIX. Master bundles conform to NEMA standard RN2.

Specification Data

To specify, Rigid Steel Conduit include the following: Rigid Steel Conduit shall be hot-dip galvanized and manufactured by Allied Tube & Conduit. Threads shall be hot galvanized after cutting. Rigid steel conduit shall be listed to UL Safety Standard 6 by a nationally-recognized testing laboratory with follow up service. It shall be manufactured in accordance with ANSI C80.1.

Note: Federal specification WW-C-581, Class 1, Type A has been superseded by UL Standard 6, which has been adopted by the federal government.

c-ul-usListed to Underwriters Laboratories Safety Standard UL 6
Manufactured in accordance with ANSI C80.1

Galvanized Rigid Conduit (GRC)

Trade SizeMetric DesignatorOutside Diameter*Nominal Wall Thickness**Approx Weight per 100 Ft (30.5M)Qty in Master Bundle***
1 1/4351.66042.160.1333.3821898.9900274.5
1 1/2411.90048.260.1383.51263119.3800244.0
2 1/2632.87573.030.1934.90559253.6370112.9
3 1/2914.000101.600.2155.46880399.225076.3
*Tolerances: Trade Size 1/2 to 1-1/2: ±0.015” (0.38mm); Trade Size 2-6: ±1%
Length equals 10 ft. (3.05m) with a tolerance of +/- .25 in. (6.35mm)
** For information only. Not a requirement of the UL standard.
***NEMA RN-3 Standard