Explore Seamless GI Pipes: 40mm, 80mm, HSN Code & Threading Details

 

 What Are Seamless GI Pipes?

Seamless GI pipes are steel pipes galvanized with a protective zinc layer and produced without welds — making them highly durable, corrosion-resistant, and ideal for high-pressure or corrosive environments.

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📏 Sizes Focus: 40mm & 80mm GI Seamless Pipes

These two sizes are widely used across plumbing, industrial air lines, and construction frameworks.

📌 40mm GI Seamless Pipe

• Nominal Bore (NB): 40mm (1½")
• Outer Diameter (OD): 48.3 mm
• Wall Thickness: 3.25 – 4.0 mm
• Weight/Meter (approx.): 3.85 – 4.45 kg
• Applications: Water pipelines, air lines, solar support structures

📌 80mm GI Seamless Pipe

• Nominal Bore (NB): 80mm (3")
• Outer Diameter (OD): 88.9 mm
• Wall Thickness: 4.5 – 5.4 mm
• Weight/Meter (approx.): 9.8 – 11.5 kg
• Applications: High-flow plumbing, industrial cooling lines, fire hydrant piping

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🧾 HSN Code for Seamless GI Pipes

✅ HSN Code: 73063090

Details	Value
HSN Code	7306 30 90
Description	Other tubes & pipes, of iron or steel, of circular cross-section, welded/seamless, plated or coated with zinc
GST Rate	18%
Used For	Invoicing, taxation, exports

🔎 Ensure correct HSN usage in invoices to avoid GST disputes.

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🔩 Threading Details

Seamless GI pipes are often pre-threaded to suit Screwed & Socketed (S&S) joints or mechanical assembly systems.

🧰 Standard Thread Types:

Thread Type	Standard	Common Use
BSPT (Tapered)	IS:554	Indian plumbing, industrial use
NPT	ANSI B1.20.1	US-based exports, refineries

🔧 Thread Details for 40mm & 80mm:

Size	TPI (Threads/Inch)	Thread Length (mm)	Socket Compatibility
40mm	11	~20 mm	GI threaded socket
80mm	8	~28–30 mm	GI heavy-duty socket

📌 Pro Tip: Use Teflon tape or thread sealant for pressure-tight connections.

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🏭 Industrial Applications

Industry	Use Case
Construction	Water risers, rainwater harvesting
HVAC & Utilities	Chilled water, compressed air
Agriculture	Irrigation mains, suction/discharge lines
Fire Safety Systems	Sprinkler pipe networks
Solar Plants	Mounting structures, panel riser frames

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🛡️ Why Choose Seamless GI Pipes?

• ✅ Leak-proof and no weld joints
• ✅ Superior mechanical strength
• ✅ Longer lifespan due to zinc coating
• ✅ Ideal for pressurized and corrosive setups
• ✅ Easy threading and compatibility with GI fittings

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💰 Price Overview (India, 2025 Estimate)

Size	Type	Rate/Metre (INR)
40mm	S&S Type	₹190 – ₹230
40mm	Plain-End	₹170 – ₹210
80mm	S&S Threaded	₹370 – ₹420
80mm	Plain-End	₹330 – ₹390

🛒 Prices may vary by zinc coating, brand (Tata, Jindal, Surya), and city.

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🏢 Recommended Suppliers in India

Company	Location	USP
Tata Pipes	PAN India	BIS-certified seamless GI pipes
Jindal (Hisar)	North India	S&S & heavy-duty threaded GI pipes
Swastik Pipes Ltd.	Delhi NCR	Bulk supply with threading customization
Zenith Steel	Gujarat	Seamless galvanized, export quality

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External Links:

• HSN Code Details from CBIC
• BIS IS:1239 Standard Overview

GMB Keywords:

• “40mm GI Seamless Pipe Price Delhi”
• “Threaded Seamless GI Pipe 80mm Dealer Near Me”

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❓ Frequently Asked Questions (FAQs)

Q1. Can I use GI seamless pipes for drinking water?
➡️ Yes, they are zinc-coated and approved for non-toxic water distribution.

Q2. What’s better – S&S or flanged joints for 80mm pipe?
➡️ S&S is faster, but for heavy-duty or underground work, flanged joints are safer.

Q3. Are these pipes suitable for gas piping?
➡️ Yes, provided pressure ratings and local gas board regulations are met.

Q4. What’s the warranty on GI seamless pipes?
➡️ Typically 5–10 years for corrosion protection depending on brand and coating thickness.