Strut Services Group, Inc.

Unistrut Alabama



P1001B3 – 1-5/8″ x 4 7/8″, 12 Gage, Triple Combination

Unistrut’s P1001B3 (triple combination), often known as 12 gauge standard or deep back-to-back strut channel, is commonly used for electrical supports, mechanical supports, pipe, conduit, duct and cable tray supports, and other general framing. For application examples, refer to our Application Showcase.

This channel is commonly used for applications with heavy load requirements such as healthcare supports, lab supports with specialized HVAC systems, and general commercial structures where P1001 material has insufficient load capacities. P1001A3 is similar to P1001B3 in load capacity but is a solution for specifiers requiring open faces of channel in the same direction for use as connection points.

Product dimensions are 1 5/8″ Long x 4 7/8″ Wide x 12 gage. thick; triple combination.

Our P1001B3 is available in the following finishes: Pre-Galvanized (PG), Hot-Dip Galvanized (HG), Plain (PL), Green (GR), Zinc Dichromate (ZD) and Stainless Steel (SS).


Part No. Length (ft) Finish Product Weight / Ft (lbs/ft)
P1001B3 10 PG 5.66
P1001B3 20 PG 5.66
P1001B3 20 HG 6.042
P1001B3 10 HG 6.042
P1001B3 10 GR 5.66
P1001B3 20 GR 5.66
P1001B3 20 PL 5.66
P1001B3 10 PL 5.66
Elements of Section – P1001B3
Area of Section 1.666 in2 (10.7 cm2)
Axis 1-1 Axix 2-2
Moment of Inertia (I) 3.639 in4 (151.5 cm4) 0.570 in4 (23.7 cm4)
Section Modulus (S) 1.493 in3 (24.5 cm3) 0.673 in3 (11 cm3)
Radius of Gyration (r) 1.478 in (3.8 cm) 0.585 in (1.5 cm)
Standard Lengths:
  • 10 feet: 10′ or 10’ 1/8” (3.05m) ± 1/8″ (3 mm)
  • 20 feet: 20′ or 20’ 3/8” (6.11m) ± 1/8″ (3 mm)
Special Lengths:
  • Available with a tolerance of ±1/8″ (3 mm). Request quote.
Curved Channel:
  • Many Unistrut channel sections can be supplied with a curve. Contact us for our ordering form, specifications, and instructions.
Load Data:
  • All beam and column load data pertains to carbon steel and stainless steel channels.
  • Load tables apply only to UNISTRUT brand channel. Look for “UNISTRUT” on the product.
  • Load tables and charts are constructed to be in accordance with the SPECIFICATION FOR THE DESIGN OF COLD-FORMED STEEL STRUCTURAL MEMBERS 2007 EDITION published by the AMERICAN IRON AND STEEL INSTITUTE USING ASD METHOD.
  • Loads are based on 33 ksi steel cold formed to 42 ksi.
  • Safety Factor to Yield Strength is 1.67 for Beam Loads and 1.80 for Column Loads.
  • Beam loads are based on a simple beam and are given as a total uniform load (W) in pounds. For proper calculation procedures, refer to our Beam Load Calculation Guide.
  • For bearing loads, reference our bearing loads page.
  • Welded channels are spot welded 2″ (51 mm) or 3″ (76 mm) on-center.

Materials & Finishes – Standard:

  • Pregalvanized (PG):  Conforms to ASTM A653 SS GR 33, G90.
  • Unistrut Defender (DF):  Conforms to ASTM A1046 SS GR 33
  • Hot Dip Galvanized (HG):  Steel conforms to ASTM A1011 SS GR 33, Finish conforms to ASTM A123
  • Perma-Green (GR):  Steel conforms to ASTM A1011 SS GR 33, E-Coat finish
  • Perma-Gold (ZD):  Steel conforms to ASTM A1011 SS GR 33, Finish conforms to ASTM B633, Type II SC3
  • Plain (PL):  Conforms to ASTM A1011 SS GR 33

Materials & Finishes – Special Metals:

  • Stainless Steel, Type 304 (SS):  ASTM A240, Type 304 *
  • Stainless Steel, Type 316 (ST):  ASTM A240, Type 316 *
  • Aluminum (EA):  ASTM B221, Type 6063-T6 (Extruded) *

* These materials have different physical properties and performance characteristics. Please contact us for design support.

Scroll to Top