Seamless vs Welded Steel Pipes: Four Key Indicators for Purchase

        In the industrial manufacturing and construction fields, seamless steel pipes and welded steel pipes are two widely used pipeline materials. Although these two types of steel pipes have many similarities in applications, they also exhibit significant differences in production processes, performance, and applicable scenarios. As a metal products supplier with 20 years of industry experience, Mate Metal Products Company will analyze from a professional perspective how to select the best pipe material according to project requirements. 

 1. Comparison of Production Processes

        Seamless steel pipes are formed in one step through hot rolling or cold drawing processes. The steel is heated to a high temperature, and then the billet is made into a tubular shape through a piercing machine. After that, by adjusting the outer diameter size and extruding the inner hole, a pipe material with the required diameter and wall thickness is formed.It has no weld line and is suitable for high-pressure environments.

        Welded steel pipes are made by rolling flat steel strips or steel plates into a tubular shape and then using electric welding technology to connect the seams. This method has lower costs, but strict requirements are placed on the strength of the welds.

  

        2. Core Performance Indicators

        (1).Pressure-bearing Capacity:Due to the absence of weld defects,the pressure-bearing strength of seamless steel pipes is generally 15-20% higher.

        (2). Dimensional Accuracy: The tolerance of cold-drawn seamless pipes can reach ±0.05mm, while that of welded steel pipes is usually ±0.15mm.

        (3). Corrosion Resistance: The grain structure of heat-treated seamless steel pipes is more uniform, extending the anti-corrosion life by 30%.   

        3. Application Scenario Selection Guide

        Areas where seamless steel pipes are preferred:

        ✅ Petroleum and natural gas transportation (API 5L standard)

        ✅ High-pressure boiler tubes (ASTM A106 specification)

        ✅ Precision instrument manufacturing 

        Occasions where welded steel pipes are recommended:

        ✅ Building structure supports (EN 10219 standard)

        ✅ Low-pressure fluid transportation

        ✅ Budget-sensitive projects 

                                            

        4.Cost-benefit analysis

        Although the unit price of seamless steel pipes is 25 - 40% higher and they require higher equipment and technical requirements during production, their longer service life can reduce the whole life cycle cost. Due to the relatively simple production process and lower cost, welded steel pipes are suitable for large-scale production and application.