Standard Physical & Mechanical Properties

• All black ERW carbon steel pipes are produced and tested in strict accordance with standard mechanical indicators, featuring stable strength, good ductility and reliable pressure resistance for conventional engineering scenarios:
  • Mechanical Performance
    • Yield Strength: ≥205MPa–345MPa (depending on steel grade); Q235B/A53 Gr.B maintains stable yield performance to resist structural deformation under normal load
    • Tensile Strength: 330MPa–550MPa, providing excellent structural tensile resistance for long-term service
    • Elongation: ≥20%, outstanding ductility and plasticity, supporting bending, cutting, welding and secondary processing without cracking
    • Impact Toughness: Stable room-temperature impact resistance, adaptable for conventional indoor and outdoor non-extreme working environments
  • Physical & Working Performance
    • Pressure Resistance: Pass 100% factory hydraulic pressure test, suitable for low and medium-pressure fluid transmission (working pressure ≤16bar)
    • Dimensional Accuracy: High roundness and straightness, uniform wall thickness, tight tolerance control, ensuring easy fitting and on-site installation
    • Weld Seam Quality: Continuous high-frequency welding with narrow and smooth weld seam, consistent mechanical properties between weld and pipe body, no welding defects
    • Surface Feature: Uniform black oxide layer, anti-rust during short-term storage and transportation, no surface peeling or oxidation failure

Core Product & Market Advantages

• Black ERW carbon steel pipes occupy dominant market share in the global conventional piping industry, with irreplaceable comprehensive advantages in cost, productivity, process and application flexibility compared with seamless pipes and SSAW/LSAW pipes:
  • Ultra-High Cost Performance: Compared with seamless steel pipes, ERW pipes have lower production costs and more competitive unit prices without sacrificing basic structural and pressure resistance performance, making them the first choice for budget-friendly mass engineering projects.
  • Stable & Reliable Welding Quality: Adopting advanced high-frequency resistance welding technology, the weld seam is fine and uniform with high bonding strength. After heat stress relief treatment, the pipe avoids weld cracking and deformation, with quality far superior to ordinary spiral welded pipes.
  • High Dimensional Precision & Easy Construction: Accurate outer diameter, wall thickness and length size, smooth inner and outer surfaces. It supports standard pipe fitting matching, reduces on-site processing difficulty, and greatly improves construction efficiency.
  • Excellent Processing & Weldability: The carbon steel material has good plasticity and weldability, convenient for cutting, bending, threading, grooving and other secondary processing, adapting to diverse construction requirements.
  • Mass Production & Fast Delivery: ERW production line features continuous rolling and high output, with sufficient conventional size inventory. It can meet large-batch order demands and shorten customer delivery cycles effectively.
  • Wide Market & Standard Compatibility: Compliant with multi-national standards, compatible with global mainstream pipe fittings and engineering specifications, easy for market promotion and project acceptance in various regions.
  • Lightweight & Practical: Lighter than thick-wall seamless pipes under the same caliber, reducing overall engineering load and transportation costs.

Global Main Application Scenarios

• With cost-effectiveness and stable performance, black ERW carbon steel pipes are widely recognized in global civilian and industrial conventional piping markets, covering:
  • Low & medium-pressure water supply and drainage pipeline systems
  • Indoor natural gas, compressed air and conventional fluid transmission pipelines
  • Fire sprinkler system pipelines (industrial & commercial buildings)
  • Construction structural support, scaffolding and steel frame engineering
  • General industrial factory circulating piping and low-pressure process pipelines
  • Agricultural irrigation and municipal conventional pipeline projects

Objective Application Limitations

• To help global customers make accurate product selection, we objectively clarify the inherent limitations of black ERW carbon steel pipes based on process and material characteristics:
  • No Anti-Corrosion Coating: Different from galvanized steel pipes, black ERW pipes have only a natural black oxide layer with limited anti-rust ability. They are prone to rust in long-term humid, outdoor or strong corrosive environments, requiring additional anti-corrosion painting, coating or wrapping treatment for outdoor projects.
  • Not Suitable for High-Pressure & Extreme Working Conditions: Restricted by welding process, ERW pipes are not recommended for high-pressure, high-temperature or sub-zero low-temperature extreme engineering scenarios, where seamless pipes or LSAW pipes are more applicable.
  • Weld Seam Inherent Attribute: As welded pipe, it has a longitudinal weld seam, which is a relatively weak structural point compared with seamless pipes, not suitable for ultra-high fatigue working conditions.
  • Limited Ultra-Thick Wall Production: ERW process is mainly for medium and thin-wall pipes, unable to produce ultra-thick wall tubes, so it cannot replace heavy-duty seamless pipes in special heavy-load projects.