EN 10305-1 seamless precision steel tube

EN 10305-1 Seamless Precision Steel Tubes

EN 10305-1 seamless precision steel tubes are high-quality cold-drawn tubes with circular cross-sections, engineered for applications requiring tight dimensional tolerances and superior surface quality.

EN 10305 seamless precision steel tube shall be manufactured from hot finished seamless tubes by cold drowning. Other suitable methods of cold working are permitted. The tubes shall be delivered in the delivery condition +N which means that after the final cold drawing operation the tubes are normalized in a controlled atmosphere.

Standard and Steel grade:

The allowed pressure rates and temperatures are the responsibility of the customer in accordance with the state of the art and in application of the safety coefficients specified in the application regulations, codes or standards.

Tubes according to this EN 10305 European standard are characterised by having precisely defined tolerances on dimensions and a specified surface roughness.

EN 10305 seamless precision steel tube shall be manufactured from hot finished seamless tubes by cold drawning. Other suitable methods of cold working are permitted. The tubes shall be delivered in the delivery condition +N which means that after the final cold drawing operation the tubes are normalized in a controlled atmosphere.

NBK means protective heat-treating under the non-oxidation enviroment to get a bright and smooth surface for the tubes.

Chemical Composition (%) of EN 10305-1

Steel grade
Name
Steel
Number
C(% max) Si(% max) Mn(% max) P(% max) S(% max)
 E215  1.0212  0.10  0.05  0.70  0.025  0.015
 E235  1.0308  0.17  0.35  1.20  0.025  0.015
 E355  1.0580  0.22  0.55  1.60  0.025  0.015

Mechanical and technological properties of EN 10305-1

Yield strength
(min Mpa)
Tensile strength
(min Mpa)
Elongation
(min %)
 215  290-430  30
 235  340-480  25
 355  490-630  22

Condition on delivery of EN 10305-1

Yield strength
(min Mpa)
Tensile strength
(min Mpa)
Elongation
(min %)
Cold-finished/hard
(cold-finished as-drawn)
BK No heat treatment after the last cold-forming process. The tubes therefore have only low deformability.
Cold-finished/soft
(lightly cold-worked)
BKW After the last heat treatment there is a light finishing pass (cold drawing) With proper subsequent processing, the tube can be cold-formed (e.g. bent, expanded) within certain limits.
Annealed GBK After the final cold-forming process the tubes are annealed in a controlled atmosphere or under vacuum.
Normalized NBK The tubes are annealed above the upper transformation point in a controlled atmosphere or under vacuum.

Note:

  • The yield point for the annealed (GBK)condition on delivery is at least 50% of the (ultimate) tensile strength. Depending upon the degree of deformation in the drawing operation, the yield point of tubes delivered in the cold-finished/hard (BK)and cold-finished/soft(BKW) conditions, may be increased to a level close to the tensile strength.
  • In calculating the yield point, the following values are recommended : cold-finished/hard condition on delivery ?80% of the tensile strength, cold-finished/soft condition on delivery ?70% of the tensile strength.

Quality grade of EN 10305-1

Seamless cold drawn precision steel tubes in acc. with EN 10305-1

The tubes are supplied in the following quality grades :

  • precision steel tubes intended primarily for mechanical stressing, without any particular quality requirement and without acceptance test certificate.
  • precision steel tubes intended primarily for mechanical stressing, with special quirement and exclusively with acceptance test certificate.
  • precision steel tubes with special requirement according to section 12.

Theses requirements and corresponding tests must be agreed, with the customer having to specify his requirements at the time of enquiry and on ordering.


Seamless cold drawn precision steel tubes in acc. with EN 10305-1

Seamless precision tubes are used wherever a high level of measuring accuracy, smooth surfaces and improved resistance values are of the essence. These tubes are available in any desired dimension

Seamless precision tubes are used for the following applications
  • Heat exchangers
  • Elevator tubes
  • Gas bottles
  • Pit props
  • HPL tubes (with phosphated, alternatively galvanised surface)
  • Hawse pipes
  • Motorbike/bicycle frames
  • Rivets
  • Pump pipes
  • Textile machine construction
  • Cylindrical pipes, piston pipes, telescopic pipes
  • Stabiliser pipes
Seamless tubes for automotive applications
  • Transmission shafts
  •  Fuel injection pipes
  • Piston pins
  • Ball cages
  • Steering systems
  • Tubes for power steering systems
  • Tubes for drive shafts

EN 10305-1 E355+SR Seamless Cold Drawn Steel Tubes

Welded cold drawn precision steel tubes in acc. with EN 10305-2

Standard EN 10305 covers steel-produced precision tubes. This standard includes delivery conditions for six different parts. Part 1 or as referred to as EN 10305-1 refers to Seamless cold drawn precision tubes. These precision tubes are specifically designated with the letter E, thereby the manufacturing processes adhere to the standard and keep tight tolerances, making them well suited for use as machine parts. This is because a precision steel tube en 10305-1 is identical to the system it is to be attached to.

Hence, there is no error, nor is there any wiggle room for a mismatch to occur in the system. Therefore the use of EN 10305-1 material to make a cold-drawn precision tube is a welcome one. In addition to being designated as machine steels, there are many grades with differing yield strengths that could be used in the production of EN 10305-1 equivalent tube.

Generally, most buyers prefer the use of steels that have minimum yield strength of about 235 N/mm2 or 355 N/mm2. The EN 10305-1 material is often designated with a relevant treatment the tubes have been processed with. For instance, the tube with the designation en 10305-1 E235+N would indicate that the steel is to be delivered in a normalized condition. There are several benefits of using an E355+SR EN 10305-1 Cold drawn seamless precision tube. Not only do they have a tighter level of tolerances, but they have better mechanical properties and hardness. Moreover, the cold drawing improves the surface of the EN 10305-1 E235+C tube as they are smoother.

EN 10305 is characterized by having exactly defined tolerances on dimensions and specified surface roughness. Typical fields of applications are in the furniture, vehicle, and general engineering industries. E235 in the pickled, normalized condition, to be delivered in standard length of 5.8 m.


Welded cold drawn precision steel tubes in acc. with EN 10305-2

Precision tubes according to EN10305-2 are manufactured in a cold forming process for stretch-reduced or HF-welded hollow sections (shell).

Welded drawn tubes are used primarily in the automotive industry, for instance as prop shafts, rubber/metal parts, drive shafts or cam shafts.

The application options for welded precision steel tubes according to EN 10305-2 are determined by specific technical characteristics, such as

  • high level of dimensional accuracy for the internal and external diameter
  • restricted tolerances for wall thickness
  • process-related smooth surfaces
  • good concentricity
  • improved resistance values through cold forming
  • freely selectable dimensions

EN10305-4 E235 E355 Cold drawn seamless precision tube

Bright precision tube Bright precision tube
Cold drawn seamless precision pipe Cold drawn seamless precision pipe

DIN2391 ST37.4,ST52.4 bright annealed and bright normalised seamless cold drawn precision steel tubes

EN10305-1 E235 E355 Bright annealed and bright normalised seamless cold drawn precision steel tubes Weldable round precision steel tubes for hydraulic distribution systems / circuits.

Cold finished bright annealed seamless steel tubes

Cold finished bright annealed seamless precision steel tube: Cold drawn, cold rolled, precision rolled.

Finish: Annealed & pickled, bright annealed, mechanically polished & electropolished.

Ends: Tapered or plain end, square cut, burr free, plastic caps on both ends.

DIN steel heat exchangers tubes

DIN steel heat exchanger tubes, meeting German Industrial Standards, are constructed from high-temperature and corrosion-resistant steel, specifically designed for efficient heat exchange applications.

Cutting steel tube

Seamless Tube Processing

With years of expertise, we provide a wide range of steel tube processing services. From basic sawing and machining to complex bending and upsetting operations, we support you at every stage of your project.

Our capabilities include eccentricity reduction and concentricity improvement through turning and grinding. We specialize in creating complex geometries using rotary swaging and axial forming, and offer property modifications through partial heat treatment to meet your exact requirements.

Our Processing Capabilities

Variable wall thicknesses
Drilling / Stamping / Lasering
Peeling / Roller Burnishing
Cold Forming
Cutting
Beveling
Deburring
Thread Rolling / Threading
Partial Hardening
Turning / Milling / Grinding
Reducing / Expanding
Swing

Our Areas of Application

A range to meet your needs

Mechanical engineering

Mechanical engineering

High-quality steel solutions for diverse mechanical engineering applications – reliable, precise, and built for performance.

Construction

Construction

Premium steel products for demanding construction projects – from bridges to offshore structures, built to last.

Automotive

Automotive

Versatile components for the automotive industry – precision, quality, and processing expertise for every application.

Plant Engineering & Energy

Plant Engineering & Energy

Robust tubes for plant engineering and energy systems – designed for extreme conditions and long-term efficiency.

Infrastructure

Infrastructure

Versatile solutions for modern infrastructure – supporting reliable supply networks and large-scale construction projects.

Hydraulics

Hydraulics

Versatile solutions for hydraulic systems – durable, pressure-resistant, and engineered for maximum reliability.

Typical Applications

  • Power generation & thermal plants
  • Boilers, superheaters, reheaters
  • Steam piping & headers
  • Heat exchangers & condensers
  • Oil & gas processing
  • Petrochemical & refining
  • Fertilizer & chemical plants
  • Nuclear power facilities

Key Advantages

  • High-temperature strength
  • Excellent pressure resistance
  • Superior corrosion & oxidation resistance
  • Long service life
  • Reduced maintenance cost
  • Good weldability & recyclability

Service Conditions

Condition Typical Application
High Temperature Boilers, superheaters, steam headers
Low Temperature Cryogenic processing systems
High Pressure Power & process piping
Corrosive Media Chemical & petrochemical plants
Creep Service Thermal power stations

Common Standards

Product Specification
Seamless Pipes ASTM A335 P1 / P5 / P9 / P11 / P22 / P91
Butt Weld Fittings ASTM A234 WP1 / WP5 / WP9 / WP11 / WP22 / WP91
Forged Fittings & Flanges ASTM A182 F1 / F5 / F9 / F11 / F22 / F91

Industries Served

Sunny Steel supplies alloy steel piping systems worldwide, supporting projects that demand certified materials, full traceability and long-term operational reliability.

  • Oil & Gas
  • Petrochemical
  • Power Generation
  • Chemical Processing
  • Mining
  • Marine Engineering
  • Refineries
  • Fertilizer Plants
  • Heavy Industry

Delivery

Steel pipe delivery status(condition)

Steel pipe delivery status(condition): cold / hard (BK), cold / soft (BKW), after cold stress relief annealing (BKS), annealing (GBK), normalized (NBK).

Condition on delivery of steel pipe

Term Symbol Explanation
Cold-finished/hard (cold-finished as-drawn) BK No heat treatment after the last cold-forming process. The tubes therefore have only low deformability.
Cold-finished/soft (lightly cold-worked) BKW After the last heat treatment there is a light finishing pass (cold drawing). With proper subsequent processing, the tube can be cold-formed (e.g. bent, expanded) within certain limits.
Annealed GBK After the final cold-forming process the tubes are annealed in a controlled atmosphere or under vacuum.
Normalized NBK The tubes are annealed above the upper transformation point in a controlled atmosphere or under vacuum.

The general cold strip mills, volume should go through continuous annealing (CAPL unit) to eliminate cold hardening and rolling stress, or batch annealing reach the mechanical properties of the corresponding standard specifies. Cold rolled steel surface quality, appearance, dimensional accuracy better than hot-rolled plate, and right-rolled thin product thickness is about 0.18mm, so the majority of users favor.

Cold rolled steel coil substrate products deep processing of high value-added products. Such as electro-galvanized, hot dip galvanized, electro-galvanized fingerprint resistant, painted steel roll damping composite steel, PVC laminating steel plates, etc., so that the excellent quality of these products has a beautiful, high resistance to corrosion, has been widely used.

Cold rolled steel coil finishing after annealing, cut the head, tail, trimming, flattening, smooth, heavy volume, or longitudinal clipboard. Cold-rolled products are widely used in automobile manufacturing, household electrical appliances, instruments, switches, buildings, office furniture and other industries. Steel plate strapping package weight of 3 to 5 tons. Flat sub-volume typically 3 to 10 tons / volume. Coil diameter 6m.

Packing

Bare packing/bundle packing/crate packing/wooden protection at the both sides of tubes and suitably protected for seaworthy delivery or as requested.

Steel pipe bundle packing
Steel pipe bundle packing
Seamless steel pipe packing
Seamless steel pipe packing
Small diameter tube packing
Small diameter tube packing

Placing steel pipes into containers

Alloy pipe loading into container
Alloy pipe loading into container
Alloy pipe loading into container
Alloy pipe loading into container
Alloy pipe loading into container
Alloy pipe loading into container

There are probably hundreds of different methods for packing a pipe, and most of them have merit, but there are two principles that are vital for any method to work: prevent rusting and sea transportation security.

Steel strips bundling for fixed pipes

  • Plastic caps plugged at the two sides of pipe ends
  • Avoid damage caused by steel strapping during transportation
  • Bundled signs should be uniform and consistent
  • The same bundle(batch) of steel pipe shall come from the same furnace.
  • The steel pipe shall have the same furnace number, steel grade and specifications.

Our packing can meet any needs of the customers.

Alloying Elements

Commonly used alloying elements and their effects are listed in the table given below.

Alloying Elements Effect on the Properties
Chromium Increases Resistance to corrosion and oxidation. Increases hardenability and wear resistance. Increases high temperature strength.
Nickel Increases hardenability. Improves toughness. Increases impact strength at low temperatures.
Molybdenum Increases hardenability, high temperature hardness, and wear resistance. Enhances the effects of other alloying elements. Eliminate temper brittleness in steels. Increases high temperature strength.
Manganese Increases hardenability. Combines with sulfur to reduce its adverse effects.
Vanadium Increases hardenability, high temperature hardness, and wear resistance. Improves fatigue resistance.
Titanium Strongest carbide former. Added to stainless steel to prevent precipitation of chromium carbide.
Silicon Removes oxygen in steel making. Improves toughness. Increases hardness ability
Boron Increases hardenability. Produces fine grain size.
Aluminum Forms nitride in nitriding steels. Produces fine grain size in casting. Removes oxygen in steel melting.
Cobalt Increases heat and wear resistance.
Tungsten Increases hardness at elevated temperatures. Refines grain size.
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