DIN / EN / ASME Certified

DIN 1630 ST52.4 and ST52.3 Carbon Steel Pipes Manufacturer in India

Unicorn Metal Industries stands as premier DIN 1630 ST52.3 Pipes Manufacturers in India, supplying certified low-alloy piping designed to withstand severe fluid loads. Modern engineering networks operating under high pressure require materials that resist bursting, high physical stress, and rapid structural fatigue. Standard utility piping often lacks the tensile integrity and yield strength necessary to handle high-performance liquid or gas transmission.

Partnering with accredited DIN 1630 ST52.4 Pipes Manufacturers in India guarantees direct access to reliable, mill-tested high-pressure piping. Our high-yield products prevent system failure, ensuring leak-proof operations in tough processing and heavy-duty structural environments.

We carry extensive inventories to meet the unique structural requirements of hydraulic assemblies and fluid lines across the globe. These specialized carbon steel profiles ensure maximum operational safety and dimensional stability across demanding industrial applications.

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Seamless Round ProfileGeometry

ST52.3 / ST52.4Available Grades

4 mm to 219 mm ODSize Range

Stack of heavy industrial DIN 1630 ST 52.4 seamless pipes with beveled ends ready for delivery

Overview

Leading Exporter of High-Performance DIN 1630 St 52-4 and St 52-3 Seamless Pipes & Tubes

The DIN 1630 standard regulates non-alloy steel circular tubes engineered specifically for high-performance fluid systems and critical pressure applications. These materials are hot-rolled or cold-drawn to ensure extreme physical toughness, exceptional dimensional control, and reliable wall-thickness distribution.

We specialize in exporting certified DIN 1630 ST 52.3 carbon steel seamless pipe and specialized DIN 1630 ST 52.4 carbon steel seamless pipe to strict global markets. Our pipelines are built to support demanding industrial fluid networks, ensuring safety and compliance across global refining and power infrastructure.

While pressure pipelines dominate our inventory, we also fabricate high-precision DIN 1630 ST 52.3 carbon steel tubes alongside high-grade DIN 1630 ST 52.4 carbon steel tubes. These high-strength tubes offer excellent concentricity and surface finishes, making them perfect for mechanical components.

Datasheet

Technical Data Sheet & Product Specifications of DIN 1630 Pipes

Our production lines accommodate a wide array of schedules and custom wall thicknesses to match your exact pipeline specifications. We supply fully certified high-pressure piping built to ASME and DIN dimensional standards.

Key Differences: DIN 1630 ST52.4 vs ST52.3 Carbon Steel Pipes

The primary difference between these two premium grades lies in their intended application and yield strength. While both are highly weldable non-alloy steels, St 52-4 is engineered primarily for high-requirement pressure systems, whereas St 52-3 is optimized for structural stability and low-temperature impact resistance.

The table below highlights the mechanical differences between these two high-performing carbon steel pipe grades:

Feature or Property	DIN 1630 ST52.4 Pipes	DIN 17121 / 17100 ST52.3 Pipes
Primary Standard	DIN 1630 (High-performance circular tubes)	DIN 17121 (Structural/mechanical) or EN 10025
Primary Intent	High-pressure fluid and gas transmission	Structural, machinery, and mechanical tubing
Minimum Yield Strength	500 MPa	355 MPa (varies slightly with wall thickness)
Tensile Strength	650 MPa	470 to 630 MPa
Elongation (A5 min)	21%	22%
EN Equivalent	EN 10216-3 Grade P355N	EN 10025 Grade S355JR / S355J2
Low-Temp Impact Test	Typically optional	Standard (e.g., Minimum 27 Joules at -20 degrees C)

Specifications of DIN 1630 ST52.4 Carbon Steel Pipes

Selecting the St 52-4 grade ensures your high-pressure fluid networks operate safely under unexpected dynamic pressure surges. This steel undergoes a silicon-killing process to remove micro-impurities, which prevents high-temperature hydrogen embrittlement.

Chemical Composition & Weldability of St 52-4

SHEET 01

Element	Maximum / Range Percentage
Carbon (C)	0.22% Maximum
Silicon (Si)	0.55% Maximum
Manganese (Mn)	1.60% Maximum
Phosphorus (P)	0.040% Maximum
Sulphur (S)	0.035% Maximum
Aluminium (Al)	0.020% Minimum

Mechanical Properties & Minimum Yield Strength of St 52-4

SHEET 02

Mechanical Property	Metric Value
Minimum Yield Strength	500 MPa
Tensile Strength	650 MPa
Minimum Elongation	21%

Equivalent Designations for DIN 1630 St 52-4 Pipes

SHEET 03

Standard	Equivalent Designation
DIN (Germany)	DIN 1630 Grade St 52-4
EN (European)	EN 10216-3 Grade P355N
BS (British)	NFA 49-211 Grade TU E275

Specifications of DIN 1630 ST52.3 Carbon Steel Pipes

The St 52-3 grade is chemically tailored to handle high structural loads while remaining incredibly easy to weld in the field. It is favored by engineering teams building structural frameworks and heavy mechanical handling equipment.

Chemical Properties of St 52-3 Carbon Steel

SHEET 04

Element	Maximum / Range Percentage
Carbon (C)	0.22% Maximum
Silicon (Si)	0.55% Maximum
Manganese (Mn)	1.60% Maximum
Phosphorus (P)	0.040% Maximum
Sulphur (S)	0.040% Maximum
Aluminium (Al)	0.020% Minimum

Mechanical Strength & Low-Temperature Impact Energy of St 52-3

SHEET 05

Performance Metric	Metric Boundary Value
Yield Strength (thickness <= 16 mm)	355 MPa Minimum
Yield Strength (16 < thickness <= 40 mm)	345 MPa Minimum
Tensile Strength (Rm)	470 to 630 MPa
Minimum Elongation (A5)	22%
Impact Test Energy	Minimum 27 Joules at -20°C

Equivalent Designations for DIN 1630 St 52-3 Pipes

SHEET 06

Standard	Equivalent Designation
DIN (Germany)	DIN 1630 / DIN 17121 ST52.3
EN (European)	EN 10025 Grade S355JR / S355J2
ASTM (USA)	ASTM A572 Grade 50
ASME (USA)	ASME SA572 Grade 50

Dimensional Standard, Size Range & Schedule Chart

SHEET 07

Specification Parameter	Available Range & Standards
Outer Diameter (OD)	4 mm to 219 mm
Wall Thickness (WT)	0.5 mm to 20 mm
Standard Pipe Length	5.8 Meters, 6 Meters, 11.8 Meters, 12 Meters, or Custom Cut Lengths
Standard Schedules	SCH 20, SCH 30, SCH 40, SCH Standard (STD), SCH 80, SCH Extra Strong (XS), SCH 120, SCH 160, SCH Double Extra Strong (XXS)
Dimensional Standards	ASME B36.10M, DIN 1630, DIN 2448, EN 10220
Pipe End Finishes	Plain End, Beveled End (30° or 37.5°), Threaded End, Screwed & Coupled

Applications

Applications of ST52.3 & ST52.4 Pipes and Circular Tubes

These structural pressure components are used in high-stress fluid and mechanical handling industries due to their remarkable tensile strength. Deploying certified seamless pipes prevents early material failure and avoids expensive plant shutdowns.

APP / 01

Hydraulic Machinery

Widely used in hydraulic cylinder lines, fluid actuators, and high-pressure system loops.

APP / 02

Chemical Processing

Excellent for non-corrosive chemical transport and process water lines operating under pressure.

APP / 03

Power Generation

Deployed in low-temperature boiler piping, auxiliary steam lines, and cooling loops.

APP / 04

Civil Engineering

Used in high-load foundations, bridge frameworks, offshore platforms, and structural supports.

Our highly durable DIN 1630 ST 52.3 seamless pipe inventories ensure your structural assemblies maintain their physical shape over time. Meanwhile, specifying DIN 1630 ST 52.4 seamless pipe ensures your pressure systems operate reliably under high continuous loads.

Quality Assurance

Quality Testing Protocols & Certified Credentials

Ensuring long-term safety in critical pressure networks requires rigorous inspection protocols before any product leaves the manufacturing floor. Any minor interior wall defect can cause a sudden rupture under high operating pressures.

Every batch we manufacture undergoes strict non-destructive testing (NDT), flattening checks, hydrostatic verification, and ultrasonic testing. Sourcing from our facility provides you with complete traceability backed by EN 10204 3.1/3.2 Mill Test Certificates.

Proven Market Authority & Official Government Certifications

CREDENTIALS

Credential / Certificate Type	Governing Authority	Legal & Trade Utility
ISO 9001:2015 Certificate	Global Quality Management	Confirms strict, traceable manufacturing procedures
EN 10204 3.1 / 3.2 MTC	Certified Material Laboratory	Provides complete chemical and mechanical heat traceability
UDYAM Registration	Government of India	Verifies micro-enterprise legal standing (UDYAM-MH-27-0009247)
IEC Code Registration	Director General of Foreign Trade	Permits seamless global exports of raw materials (IEC: 0314032398)

View & Download Our Full-Resolution Quality Certificates

FAQ

Frequently Asked Questions About DIN 1630 Pipes

What is the main difference between DIN 1629 and DIN 1630 standards?

While both standards cover seamless non-alloy steel circular pipes, DIN 1630 is engineered with stricter chemical controls and testing protocols to support special high-performance pressure operations.

Can DIN 1630 ST 52.4 pipes be easily welded in the field?

Yes. Thanks to its low carbon limit of 0.22%, this grade offers excellent weldability using standard methods like MIG, TIG, or submerged arc welding without requiring extensive preheating.

What are the recommended welding procedures for DIN 1630 ST52.3 and ST52.4 pipes?

Both grades feature a low carbon limit of 0.22 percent, providing excellent weldability in the field. They can be joined easily using standard methods like TIG, MIG, or stick welding without requiring extensive preheating for standard walls.

Can DIN 1630 ST 52.3 carbon steel tubes be used at low operational temperatures?

Yes, ST 52.3 carbon steel tubes are engineered to absorb sudden kinetic shocks without cracking. Equivalent grades like S355J2 are tested for impact toughness, making them reliable for structural piping down to -20 degrees C.

What makes DIN 1630 ST 52.4 seamless pipes suitable for hydraulic applications?

With a high yield strength of 500 MPa and uniform grain structure, ST 52.4 seamless pipes easily handle high internal fluid pressures. This precise dimensional control prevents bursting, making them ideal for heavy-duty hydraulic cylinders and fluid loops.