Understanding Pipe Schedules: Sizes in mm and Inches for
Fabrication & Industrial Use
Introduction
In fabrication, welding, and industrial piping, accuracy matters. One of the most
important concepts is pipe schedules— the system that defines pipe wall thickness and
strength. Whether you’re working in oil & gas, construction, or general fabrication,
knowing pipe schedules helps ensure safety, compatibility, and efficiency.
At Grand Tools, we design our jacks, clamps, and handling solutions to match industry
standards, making them reliable partners for pipe fitters and fabricators worldwide.
What is a Pipe Schedule?
A pipe schedule (SCH) refers to the wall thickness of a pipe. The higher the schedule
number, the thicker the pipe wall.
- Schedule 40 = Standard wall thickness (common in most industries).
- Schedule 80 = Extra strong, used where higher pressure or durability is needed.
- Schedule 160 and XXS = Very thick walls, for high-pressure, specialized use.
Why Pipe Schedule Matters
- Strength & Safety – Thicker walls handle higher pressure.
- Compatibility – Proper sizing ensures accurate fittings and joints.
- Cost Efficiency – Avoid over-specifying heavy pipes when lighter ones are sufficient.
- Fabrication Needs – Correct sizing is crucial when working with pipe jacks, clamps, and material handling equipment.
Pipe Schedule Conversion Chart (Inches & mm)
Here’s a handy reference table for common pipe sizes.
| Nominal Pipe Size (NPS, inch) |
DN (mm) |
Outside Diameter (OD, mm) |
Schedule 40 Wall Thickness (mm) |
Schedule 80 Wall Thickness (mm) |
| 1/2″ |
DN 15 |
21.3 mm |
2.77 mm |
3.73 mm |
| 3/4″ |
DN 20 |
26.7 mm |
2.87 mm |
3.91 mm |
| 1″ |
DN 25 |
33.4 mm |
3.38 mm |
4.55 mm |
| 1 1/2″ |
DN 40 |
48.3 mm |
3.68 mm |
5.08 mm |
| 2″ |
DN 50 |
60.3 mm |
3.91 mm |
5.54 mm |
| 3″ |
DN 80 |
88.9 mm |
5.49 mm |
7.62 mm |
| 4″ |
DN 100 |
114.3 mm |
6.02 mm |
8.56 mm |
| 6″ |
DN 150 |
168.3 mm |
7.11 mm |
10.97 mm |
| 8″ |
DN 200 |
219.1 mm |
8.18 mm |
12.70 mm |
| 10″ |
DN 250 |
273.0 mm |
9.27 mm |
12.70 mm |
| 12″ |
DN 300 |
323.9 mm |
9.53 mm |
17.48 mm |
This is a simplified chart for common pipe sizes. For larger or specialized schedules
(e.g., SCH 160, XXS), refer to detailed standards like ASME B36.10M.
Applications in Fabrication & Industry
- Schedule 40 pipes are common in water systems, fabrication, and structural work
- Schedule 80 pipes are used in chemical plants, oil & gas, and heavy-duty applications where strength is critical.
- Choosing the right schedule avoids safety risks and ensures compatibility with tools.
Fabricators often rely on pipe jacks, stands, and clamps that can safely hold these pipes
during welding and fitting operations.
Applications Across Industries
Pipe schedules are used in almost every industry we work with, including:
- Oil & Gas
- Construction & Infrastructure
- Shipbuilding & Marine
- Chemical & Process Industries
- Water Treatment & Plumbing
How Grand Tools Supports Pipe Work
At Grand Tools, our products are built with fabricators in mind:
- G-FOLD Jack – Foldable mechanical pipe jack with strong load capacity, designed for quick setup and storage.
- Pipe Clamps & Welding Fixtures – Precise alignment for pipes across different schedules.
- Material Handling Carts – Safe transport of heavy pipes and fittings.
Our tools are tested for durability and designed to work seamlessly with the most
common pipe sizes and schedules used worldwide.
Conclusion
Understanding pipe schedules is essential for every fabricator, welder, and engineer. By
knowing the right pipe size and wall thickness, you ensure safety, compatibility, and
efficiency in every project.
At Grand Tools, we provide the right solutions to support your pipe work — from jacks
and clamps to material handling equipment.
