← Back to Bead BoardSteel tubing weight calculator
Round steel tubing — ERW and DOM — by the OD and wall thickness you actually buy. 1 inch × 0.120 wall is 1.13 lb/ft. 2 inch × 0.250 wall is 4.68 lb/ft. Enter your dimensions, get the weight per piece and the total for your cut list. No NPS, no schedule numbers — those are for pipe. This is mechanical and structural tube.
Quick answer
Calculate steel round tube weight by outside diameter and wall thickness.
Weights are calculated from published densities and standard section geometry. Real plate and bar stock runs ±2–3% from spec.
Steel round tube weight per foot
Formula: π × ((OD/2)² − (ID/2)²) × length × 0.2836 lb/in³. The industry shortcut 10.68 × (OD − wall) × wall gives the same result. ASTM A513 defines seven types of mechanical tubing: Types 1A/1B and 2 are as-welded ERW, Types 3–4 are sink-drawn, Type 5 is DOM (drawn over mandrel), and Type 6 is smooth-ID. Standard mill lengths are 20–24 ft for ERW, 4–8 ft random for DOM.
Questions welders ask about this one
What is the difference between steel tube and steel pipe?
Pipe is sized by NPS (Nominal Pipe Size) and comes in schedules (40, 80, XXS). Tube is sized by actual outside diameter and wall thickness. A "2 inch pipe" has an OD of 2.375 inches. A "2 inch tube" has an OD of exactly 2.000 inches. The weight math is the same formula, but the numbers are different because the dimensions are different.
What is DOM tubing?
Drawn Over Mandrel. It starts as ERW (electric resistance welded) tube, then gets drawn through a die and over a mandrel to refine the weld seam and tighten tolerances. DOM has a smoother interior, more uniform wall thickness, and better concentricity than ERW. The weight for a given OD and wall is identical — DOM is a finishing process, not a different alloy.
How much does 2 inch steel tubing weigh per foot?
It depends on the wall thickness. 2" OD × 0.065" wall (16 ga) is 1.34 lb/ft. 2" × 0.120" (11 ga) is 2.41 lb/ft. 2" × 0.250" (1/4" wall) is 4.68 lb/ft. The wall thickness makes a bigger difference than most people expect — going from 16 ga to 1/4" wall more than triples the weight.
What gauge is 0.120 inch wall tubing?
11 gauge. Common wall thicknesses and their gauge equivalents: 0.035" is 20 ga, 0.049" is 18 ga, 0.065" is 16 ga, 0.083" is 14 ga, 0.095" is 13 ga, 0.120" is 11 ga. Above 11 ga, most shops refer to wall thickness in fractions (3/16", 1/4", 3/8") rather than gauge.
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