Why are most steel pipes 6 meters per piece, rather than 5 meters or 7 meters?
On many steel procurement orders, we often see: “Standard length for steel pipes: 6 meters per piece.”
For example, welded pipes, galvanized pipes, square and rectangular pipes, seamless steel pipes, etc., mostly use 6m as the standard single-piece length. Why not 5 meters or 7 meters? This isn't just an industry “habit,” but rather the result of multiple factors.
6 meters is the “fixed-length” range for most steel pipes
Multiple national steel standards (e.g., GB/T 3091, GB/T 6728, GB/T 8162, GB/T 8163) explicitly stipulate: Steel pipes may be produced in fixed or non-fixed lengths.
Common fixed length: 6m ± tolerance. This means 6 meters is the nationally recognized and most prevalent base length.
Production Equipment Determination
Welded pipe production lines, square and rectangular tube forming units, cold drawing mills, straightening machines, and hot-rolled pipe fixed-length systems—6 meters is the most suitable length for most rolling mills and welded pipe forming lines. It is also the easiest length to control for stable production. Excessive length causes: unstable tension, difficult coiling/cutting, and processing line vibration. Too short a length leads to reduced output and increased waste.
Transportation constraints
6-meter pipes:
- Avoid oversize restrictions
- Eliminate transport risks
- Require no special permits
- Facilitate loading/unloading
- Offer lowest costs
7–8-meter pipes:
- Increase transport complexity
- Heighten oversize risks
- Significantly raise logistics costs
6 meters is optimal for construction: low waste, straightforward cutting, and common post-cut segment requirements (3 m, 2 m, 1 m).
Most installation and processing scenarios demand pipe segments between 2–3 meters.
6 meter length can be precisely cut into 2×3 m or 3×2 m sections.
5 meter length often requires additional welding extensions for many projects;
7 meter lengths are cumbersome to transport and hoist, and more prone to bending deformation.
The 6-meter length became the most common standard for steel pipes because it simultaneously meets: national standards, production line compatibility, transportation convenience, construction practicality, material utilization, and cost minimization.
Post time: Dec-02-2025
