Cast Iron Pipe Weight Chart, Standards(4″–15″, Std & XH)

Time:2025-06-13

After installing countless cast iron pipes, I can confirm their weight varies dramatically by size and wall thickness. A standard 10-foot length of 4-inch diameter cast iron pipe weighs around 40 lbs (18 kg), while a 6-inch diameter pipe of the same length tips the scales at nearly 70 lbs (32 kg).

Cast Iron Pipe Weight Chart
Cast Iron Pipe Weight Chart

1. What Is Cast Iron Pipe?

Cast‑iron pipe is a hollow, strong iron alloy with 2–4 % carbon and other elements. It’s been used for centuries in water and wastewater systems, valued for rigidity and longevity.

There are two main types:

  • Grey cast iron (brittle, machinable)

  • Ductile iron (nodular graphite, more flexible, higher strength).

In engineering contexts, “cast iron pipe” typically refers to grey iron for soil/drainage and ductile for mains. In my career, I’ve seen both, but the weight questions often come down to grey cast‑iron soil pipe.

2. Materials, Standards & Nomenclature

2.1 Material Composition:

Grey cast iron: ~3.4 % C, 1.8 % Si, ~0.5 % Mn. Ductile iron: similar but with magnesium and spheroidal graphite.

2.2 Pipe Size Standards:

  • Nominal Pipe Size (NPS) in North America aligns roughly with internal diameter.

  • BS 78 (UK, 1917) classified cast‑iron water pipe by Classes A‑D with set OD/ID dimensions.

  • ASTM & CISPI standards govern soil pipe: ASTM A–888, CISPI 301 for hubless (no‑hub) cast‑iron soil pipe.

  • EN 877 covers cast‑iron fittings for drainage in buildings.

These standards impact wall thickness and OD, which directly affect weight.

3. How Heavy Is Cast Iron Pipe?

3.1 Weight Data: Standard & Extra‑Heavy Soil Pipe

Here are typical weights per foot for ten‑foot grey cast‑iron soil pipe, as per Kinetics & Empire tables:

Nom. Size (in) Std‑Weight (lb/ft) Std‑Weight⁺Water X‑Heavy (lb/ft) X‑Heavy⁺Water
2″ 4.1 ~5.4 4.5 ~5.9
3″ 6.0 ~9.0 8.4 ~11.5
4″ 7.9 ~13.2 10.5 ~15.9
6″ 12.4 ~24.4 15.7 ~28.0
8″ 18.1 ~39.6 24.6 ~46.4
10″ 26.0 ~59.6 37.5 ~71.5
12″ 34.6 ~83.1 47.1 ~96.1
15″ 52.5 ~130.7 67.6 ~144.2

Water weight added for context.

3.2 Hubless (No‑Hub) vs. Single/Double Hub

Hubless soil pipe is lighter due to thinner hubs, but weight per foot is similar barrel‑wise. Ten‑foot bundles (e.g. 6″ x10′ = ~118 lbs per pipe) are commonly used .

3.3 Factors Affecting Weight

  • Pipe length (standard 10′ sections; 5′ exist too)

  • Wall class/pressure rating (std vs. extra‑heavy)

  • Material type (grey vs. ductile)

  • Coatings and linings (cement, asphalt) add small mass

In short: heavier classes = more material = more weight.

4. Comparison with Other Pipe Materials

Here’s how grey cast‑iron stands against alternatives:

Material �� lb/ft (6″ pipe) Notes
Grey Cast‑Iron ~12.4–15.7 Durable, heavy
Ductile Iron ~16–21 (approx.) Similar dimensions, stronger
PVC ~2–3 Lightweight, flexible
HDPE ~1.6–2.5 Lightweight, corrosion‑resistant
Steel (SCH 40) ~8–10 Medium weight, weldable

Cast‑iron is heavy, but medieval in robustness—remains in specs for decades.

5. Handling, Transport & Safety

I always say: “Don’t under‑estimate it—cast‑iron is deceptively heavy.”

Risks:

  • Manual lifting may exceed safe load limits → use proper team or mechanical means

  • Bundles can exceed 2,000 lb for 10 pipes → forklift recommended

  • On‑site storage: pipes must be racked to prevent rolling

Mitigation:

  • OSHA/ANSI‑compliant pipe‑cradles/slings

  • Gaskets protect edges when moving

  • PPE: gloves, steel‑toe boots, hardhats

It’s common jargon: “chunk of iron”—but truly, safe handling matters.

6. ISO & EN Standards (Europe & Beyond)

Outside North America, European standards apply:

  • ISO 2531 / EN 545 / EN 598 specify ductile/cast‑iron mains for water/sewer by DN size, wall class (e.g., K9, K10).

Example: DN150 (≈6″) under Class K9, wall = 5 mm, OD = 170 mm (~6.7″). Weight ~49 lb/ft according to manufacturer data .

7. Case Study: Municipal Trench Project

Context: City X replaces 600 LF of 8″ extra‑heavy cast‑iron on Main St.

Challenges:

  • 10‑foot sections weigh ~24.6 lb/ft → ~246 lb per piece

  • Bundled weight ~1,968 lb (8 pieces/bundle)

Plan:

  1. Crane offsite to jobsite

  2. Rigged slings, PVC cushion

  3. Bespoke trench bents to cradle pipes

  4. Safety watchers observe pinch‑points

Result: Zero incidents over 2‑week install.
Lesson: Planning overcomes brute weight.

8. Key Takeaways

  • Cast‑iron pipes weigh 4–70 lb/ft depending on size/class.

  • Water weight matters—fully loaded pipes may double the total.

  • Standards (ASTM, CISPI, ISO) define dimensions/weight.

  • Safety planning is crucial—these are bricks on a stick.

  • It compares unfavorably in weight to plastic, but wins in durability, sound attenuation, life‑cycle.

🔍 FAQs

Q1: How much does a 4″ cast‑iron pipe weigh?
A: Standard 10′ length = ~79 lb, or 7.9 lb/ft. Extra‑heavy (XH) = ~105 lb, or 10.5 lb/ft.

Q2: Does filled cast‑iron pipe weigh significantly more?
A: Yes. Example: 4″ std pipe barrel = 7.9 lb/ft, water adds ~5.3 lb/ft → total ~13.2 lb/ft. For extra‑heavy, up to ~15.9 lb/ft .

Q3: Are there lighter alternatives?
A: PVC, HDPE, and steel options weigh far less—typically 1–3 lb/ft for plastics, 8–10 lb/ft for steel. But cast‑iron has unmatched robustness and sound damping.

Q4: What are the handling guidelines for cast‑iron pipe?
A: Use mechanised lifting above ~150 lb, cradle support, gaskets, PPE, team‑lift if manual. OSHA and ANSI standards apply.

Q5: How do European standards affect weight?
A: ISO/EN specify wall thicknesses per DN/class (e.g., DN150–5 mm wall). Manufacturer data (e.g., Class K9) indicate ~49 lb/ft for 6″ nominal pipe .

Official References

Statement: This article was published after being reviewed by Luokaiwei technical expert Jason.

Global Solutions Director

Jason

Global Solutions Director | LuoKaiWei

Jason is a seasoned expert in ductile iron technology, specializing in the development, application, and global promotion of ductile iron pipe systems. Born on August 13, 1981, he earned his Bachelor of Science in Materials Science and Engineering with a minor in Mechanical Engineering from the University of Nevada, Reno.

Since joining Luokaiwei in 2015, a leading manufacturer of ductile iron pipes and fittings, Jason has played a pivotal role in advancing the company’s product line and expanding its global reach. His responsibilities encompass research and development, technical sales, and providing expert consultation on the selection and installation of ductile iron pipelines. Leveraging his deep understanding of materials science, Jason offers tailored solutions to clients worldwide, ensuring optimal performance and longevity of infrastructure projects.

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