A 4 inch Schedule 40 pipe is one of the most commonly used steel pipe sizes in industrial, commercial, and infrastructure projects. Known for its balanced combination of strength, wall thickness, and cost efficiency, this pipe specification is widely utilized in fluid transportation, structural construction, mechanical systems, oil & gas facilities, and water distribution networks. Understanding 4 inch Schedule 40 pipe dimensions helps engineers, contractors, and procurement professionals select the right piping solution for their applications.
The term “4 inch” refers to the nominal pipe size (NPS), while “Schedule 40″ indicates the wall thickness category. Although the nominal size is 4 inches, the actual outside diameter and wall thickness are defined by industry standards. Schedule 40 pipes are designed to provide sufficient pressure resistance while maintaining practical weight and installation efficiency.
4 Inch Schedule 40 Pipe Dimensions
| Specification | Dimension |
| Nominal Pipe Size (NPS) | 4 inch |
| Outside Diameter (OD) | 4.500 in (114.3 mm) |
| Wall Thickness | 0.237 in (6.02 mm) |
| Inside Diameter (Approx.) | 4.026 in (102.3 mm) |
| Weight | 10.79 lb/ft (16.07 kg/m) |
4 inch Schedule 40 pipes are manufactured from various materials, including carbon steel, stainless steel, galvanized steel, and alloy steel. Depending on the application, they can be produced through seamless or welded manufacturing processes. These pipes are commonly supplied according to ASTM, API, and other international standards to ensure dimensional accuracy, mechanical performance, and long-term reliability.
Due to their versatility, 4 inch Schedule 40 pipes are widely used in industrial piping systems, fire protection networks, HVAC installations, structural support applications, water treatment facilities, and energy infrastructure projects. Their moderate wall thickness provides dependable pressure handling capabilities while remaining economical for large-scale installations.
Modern industries often select Schedule 40 pipes because they offer an excellent balance between strength and material efficiency. In construction and engineering projects, these pipes can be coated, painted, galvanized, or lined to improve corrosion resistance and extend service life in challenging environments. Proper material selection and specification compliance help ensure optimal performance throughout the project lifecycle.
BESTAR TUBES supplies high-quality Schedule 40 steel pipes and customized tubing solutions for global customers. With advanced manufacturing technology, strict quality management systems, and extensive industry expertise, the company delivers reliable steel pipe products for construction, infrastructure, energy, and industrial applications worldwide.
FAQ About 4 Inch Schedule 40 Pipe Dimensions
1. What is the outside diameter of a 4 inch Schedule 40 pipe?
A 4 inch Schedule 40 pipe has an outside diameter of 4.500 inches (114.3 mm).
2. What is the wall thickness of a 4 inch Schedule 40 pipe?
The standard wall thickness is 0.237 inches (6.02 mm).
3. What industries commonly use 4 inch Schedule 40 pipes?
These pipes are widely used in construction, oil & gas, water treatment, HVAC systems, fire protection, and industrial piping applications.
4. Are 4 inch Schedule 40 pipes available in different materials?
Yes. They can be manufactured in carbon steel, stainless steel, galvanized steel, and various alloy steel grades depending on project requirements.
Post time: Jun-02-2026