What is DN and NPS in pipe sizing?

DN (Diamètre Nominal) is the metric designation, NPS (Nominal Pipe Size) is the imperial equivalent. They are not direct diameter measurements but nominal identifiers. For example, DN 50 = NPS 2 = 60.3 mm OD.

What does pipe schedule mean?

Schedule (Sch) defines the wall thickness for a given pipe OD. Higher schedule = thicker wall = higher pressure rating. Common schedules: 10 (thin), 40 (standard), 80 (extra strong), 160 and XXS for high pressure.

What is the difference between ISO 4200 and ASME B36.10?

Both define steel pipe dimensions. ISO 4200 is the international standard, ASME B36.10 is the American standard. The OD values are identical since they share the same heritage. Wall thicknesses for common schedules match between both standards.

How do I calculate pipe weight per meter?

Weight per meter = π × (OD − t) × t × ρ / 1000, where OD and t are in mm, and ρ for steel ≈ 7850 kg/m³. This gives weight in kg/m.

What is the standard OD for DN 100 pipe?

DN 100 (NPS 4) has an OD of 114.3 mm. Wall thickness depends on schedule: Sch 10 = 3.05 mm, Sch 40 = 6.02 mm, Sch 80 = 8.56 mm.

Free Engineering Tool — #149

Steel Pipe Dimensions — ISO 4200

Look up OD, wall thickness, ID, and weight per meter for standard steel pipe sizes. Select DN or NPS and schedule.

ISO 4200ASME B36.10Sch 10/40/80

Pipe Data

Selected Pipe

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Schedule	OD (mm)	Wall (mm)	ID (mm)	Weight (kg/m)

Pipe Weight Formula

OD — outside diameter (mm)
t — wall thickness (mm)
ρ — steel density ≈ 7850 kg/m³

Schedule vs Pressure Class

Schedule number ≈ 1000 × P/S, where P is internal pressure (psi) and S is allowable stress (psi). Higher schedules handle higher pressures. Sch 40 is the most common for general service.

⚠️ Note: Always verify pipe dimensions from manufacturer data for critical applications. Tolerances per ISO 4200 and ASME B36.10 apply.

Steel Pipe Dimensions ISO 4200 | DN/NPS Lookup Tool

Published by Nikolai Shelkovenko on February 15, 2026 March 5, 2026

Pipe Data

Pipe Weight Formula

Schedule vs Pressure Class