Quick Summary
1.0566 is a European standard (EN) designation for a specific grade of carbon-manganese steel. When used for seamless pipes, it is known for its good strength, toughness, and weldability. It is a very common and versatile steel grade used for mechanical and structural applications, as well as for pressure purposes.
1. Material Specification and Chemical Composition
The number "1.0566" comes from the German DIN W-Nr. (Werkstoffnummer) system, which was adopted into the European EN standard.
EN Standard: EN 10297-1: Seamless steel tubes for mechanical and engineering purposes.
Equivalent Grade Name: In this standard, 1.0566 is more commonly referred to as E355 (where 'E' stands for Engineering steel).
Similar/Equivalent Grades:
DIN: 1.0566
EN: E355 (EN 10297-1)
ASTM A519 (Mechanical Tubing): 1026, 1035 (similar but not exact equivalents)
AISI/SAE: 1026, 1035
EN 10083-2: C35 (for steel, not specifically pipe)
Typical Chemical Composition (Weight %):
| Element | Carbon (C) | Manganese (Mn) | Silicon (Si) | Phosphorus (P) | Sulfur (S) |
|---|---|---|---|---|---|
| Content | 0.30 - 0.37% | 0.50 - 0.80% | 0.15 - 0.35% | ≤ 0.025% | ≤ 0.025% |
(Note: Exact ranges can vary slightly depending on the manufacturer and specific heat analysis.)
2. Key Characteristics and Properties
The properties of 1.0566 steel are a direct result of its carbon and manganese content.
Good Strength: The carbon content (medium carbon) provides good tensile strength and yield strength, superior to low-carbon steels like E235 or E355.
Good Toughness: It offers a favorable balance between strength and ductility, allowing it to absorb energy and deform without fracturing.
Excellent Machinability: It is known for being relatively easy to machine compared to many alloy steels, making it a favorite for parts requiring turning, milling, or drilling.
Weldability: It can be welded, but requires more care than lower carbon steels. Pre-heating and post-weld heat treatment are often recommended to prevent cracking, especially in thicker sections.
Hardenability: It can be hardened by heat treatment (quenching and tempering) to achieve even higher strength levels, though it is often used in the normalized or hot-finished condition for pipes.
Typical Mechanical Properties (for seamless pipe in normalized condition):
Yield Strength (Rp0.2): Min. 355 MPa
Tensile Strength (Rm): 490 - 630 MPa
Elongation (A): Min. 22%
3. Common Applications of 1.0566 Seamless Pipes
Due to its balanced properties, 1.0566 seamless pipes are used in a wide range of industries:
Mechanical Engineering and Machinery:
Hydraulic and pneumatic cylinders
Piston rods
Shafts, spindles, and axles
General mechanical components and structural parts
Automotive Industry:
Chassis components
Shock absorber housings
Drivetrain parts
Construction:
High-strength structural components
Support columns and pillars (where more strength than standard structural steel is needed)
General Fabrication:
Any application requiring a strong, reliable, and machinable hollow steel section.
4. Why Choose a Seamless Pipe?
The "seamless" manufacturing process (where a solid billet is pierced and rolled into a hollow pipe without any weld seam) offers distinct advantages:
Uniform Strength: No weak seam, resulting in consistent mechanical properties and strength around the entire circumference.
High Pressure Resistance: The homogeneous structure makes it ideal for containing high internal pressures.
Better Ovality and Wall Consistency: Generally has better dimensional control, especially in heavier wall thicknesses.
Reliability: The absence of a weld eliminates the risk of seam-related failures.
Summary Table
| Feature | Description |
|---|---|
| Standard | EN 10297-1 |
| Common Name | E355 |
| Material Number | 1.0566 |
| Type | Carbon-Manganese Steel |
| Key Properties | Good strength, toughness, machinability, weldable with care |
| Main Advantage | Versatile, balanced properties for a wide range of applications |
| Common Forms | Seamless pipes & tubes |
| Typical Uses | Hydraulic cylinders, shafts, mechanical parts, automotive components |
Conclusion
1.0566 (E355) seamless steel pipe is a high-quality, general-purpose engineering steel. Its excellent combination of strength, machinability, and availability makes it a go-to choice for manufacturers and engineers across various sectors who need a reliable and strong tubular component. When sourcing, always ensure the material certificate (e.g., EN 10204 3.1) is provided to verify the chemical and mechanical properties.
