Standard Stainless Steel Pipe Sizes & Dimensions Table

 When it comes to stainless steel piping, accuracy in size and dimension is crucial for system performance, pressure handling, and structural compatibility. At Udhhyog, we supply ISI and ASTM-standard stainless steel (SS) pipes in a wide variety of diameters, schedules, and wall thicknesses, suitable for both industrial and architectural applications.

This guide covers the standard SS pipe sizes and dimensions to help buyers, engineers, and contractors make the right choice.

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📘 SS Pipe Size Standards Explained

Stainless steel pipes are generally defined by two parameters:

• Nominal Pipe Size (NPS) – a standard designation of pipe diameter

• Schedule (SCH) – indicates wall thickness

The outer diameter (OD) of a pipe remains fixed for a given NPS, while the wall thickness and inner diameter (ID) vary based on the schedule.

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📊 Stainless Steel Pipe Dimensions Table (ASTM A312 / A358)

NPS (Inch)	OD (mm)	SCH 10 (mm)	SCH 40 (mm)	SCH 80 (mm)
½”	21.34	1.65	2.77	3.73
¾”	26.67	1.65	2.87	3.91
1”	33.40	2.77	3.38	4.55
1¼”	42.16	2.77	3.56	4.85
1½”	48.26	2.77	3.68	5.08
2”	60.33	2.77	3.91	5.54
2½”	73.03	3.05	5.16	7.01
3”	88.90	3.05	5.49	7.62
4”	114.30	3.05	6.02	8.56
6”	168.28	3.40	7.11	10.97
8”	219.08	3.76	8.18	12.70
10”	273.05	4.19	9.27	15.09
12”	323.85	4.57	9.53	17.48

✅ Note: Udhhyog provides SS pipes in both metric (mm) and imperial (inch) standards. Dimensions vary based on tolerance class.

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🔍 Quick Explanation of Table Terms

• OD (Outer Diameter): Constant for a given NPS

• SCH 10 / 40 / 80: Wall thickness increases with schedule number

• ID (Inner Diameter): Varies depending on wall thickness

To calculate ID:
ID = OD – 2 × Wall Thickness

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🏭 Udhhyog Stainless Steel Pipe Range

✅ Available Grades:

• SS 304 / 304L

• SS 316 / 316L

• SS 310, 321 (on request)

✅ Standards Supported:

• ASTM A312 / A269 / A554

• IS 1239 (for some SS decorative use)

• JIS and EN standards

✅ Shape Options:

• Round, Square, Rectangular

• Seamless & Welded (ERW/TIG)

✅ Finishes:

• Mill finish

• Satin (Matte)

• Mirror polish

• Electro-polished (for pharma/food)

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🧾 Udhhyog Value-Added Services:

• 📏 Cut-to-length

• 🧰 Custom fabrication

• 🔩 Beveled or threaded ends

• 🧾 Mill Test Certificate (MTC)

• 🚚 PAN India fast delivery

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🧠 Frequently Asked Questions – SS Pipe Sizes

❓ Q1: What is the difference between NPS and OD?

Answer: NPS (Nominal Pipe Size) is a naming convention. Actual OD is always slightly larger and varies with NPS. For example, NPS 1" has an OD of 33.4 mm.

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❓ Q2: How do I select the correct pipe size?

Answer: Determine:

• Flow requirement (affects ID)

• Pressure rating (choose appropriate SCH)

• Compatibility with fittings
  Udhhyog can help with size selection for your application.

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❓ Q3: What is SCH 40 in SS pipe?

Answer: SCH 40 indicates standard wall thickness, commonly used for pressure piping, industrial, and general utility lines.

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❓ Q4: Are these pipes food-grade?

Answer: Yes, SS 304 and SS 316 pipes from Udhhyog are food-grade and safe for RO, water supply, dairy, and pharma use.

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❓ Q5: Can I get pipes in custom OD or thickness?

Answer: Yes. Udhhyog offers custom manufacturing for bulk orders. We also supply non-standard wall thicknesses upon request.

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❓ Q6: How do I calculate pipe weight using dimensions?

Answer:
Use formula:
Weight (kg/m) = (OD - Wall Thickness) × Wall Thickness × 0.02491 × 1000

Or request Udhhyog’s ready SS Pipe Weight Chart.