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  • Structural Hollow Sections - Celsius®

    Steel hollow sections are the most versatile and efficient form for construction and mechanical applications.

    Many of the strongest and most impressive structures in the world today would not have been possible without hollow sections.

    • Celsius 420: Raising standards in structural steel

      Celsius 420 is our next-generation steel.

      Developed in conjunction with our customers, it delivers significant weight savings and helps to cut construction time and costs on site, as it enables you to use smaller foundations and fewer temporary structures.

    • Celsius 355 Hot finished structural hollow section

      You can rely on Celsius 355 to perform in even the most challenging conditions.

      The ultimate hot finished hollow section, its unique strength and weldability allow it to be used for all structural and mechanical applications, including columns, space frames, lattice beams and trailer frames.

    Contact us

    Tata Steel

    PO Box 101

    Weldon Road, Corby

    Northants NN17 5UA

    T +44 (0)1536 402121

    F +44 (0)1536 404111

    Overview

    Celsius® 420 - Hot finished structural hollow sections

    Celsius® 420 is the next generation in hot-finished structural steel. A new steel grade yields greater strength of 420 MPa, requiring less welding, foundations and temporary structures onsite, and offers weight saving capabilities for more cost-effective construction.

    A choice of circular, square, rectangular and elliptical hollow sections can help specifiers meet a broad range of design requirements, while Celsius® 420’s tight corner radii exceeds industry standards to reduce the risk of fracture and deliver improved visual appeal.

    Celsius® 420 - Key product features

    • Normalised fine grain steel, so free of internal stresses and with a minimum strength of 420 MPa – allowing the highest fabrication factors and enabling material cost savings and lighter structures
    • Available in a wide range of circular, square, rectangular and elliptical hollow sections
    • Tight corner radii, exceeding the standard - enhancing the product’s aesthetic appeal whilst avoiding the risk of brittle fracture which occurs in some cold formed products
    • Dimensional consistency, high levels of formability and, because the steel is fully killed, excellent weldability
    • Certified as suitable for all structural applications, fully compliant with design codes and overcomes design risks associated with other forms of hollow sections
    • Certified as suitable for mechanical applications, especially those involving cyclic loading
    • Suitable for low temperature applications (40J @ -20°C)
    • Batch-tested to give the properties of the specific delivered material; full test certification supplied
    • Clearly marked as Celsius® 420, with the reassurance of batch traceability
    • Full technical support available
    • Excellent supply availability through approved stockholders
    • All Celsius® 420 material is CE marked and is fully compliant with the Construction Products Regulation
    • Suitable for galvanising with guaranteed silicon content between 0.15 and 0.25%
    • Guaranteed CEV 0.45 max compared to standard of 0.5 CEV.

    Celsius® 355 - Hot Finished Structural Hollow Sections

    Our Celsius® 355 product is the Ultimate Structural Hollow Section and is a hot finished product that offers a wide range of benefits. Made exclusively from normalised, fine grain steel with a yield strength of 355 N/mm2.

    Celsius® 355 is fully stress-relieved with uniform mechanical properties and manufactured to the standard grade EN 10210 S355 NH. Other grades, including those with improved impact qualities are available on request. 

    The strength and weldable qualities of Celsius® 355 mean that it can be used for all structural and mechanical applications, including multi-storey columns, space frames, lattice beams and frames for machinery and trailers.

    Celsius® 355 is available in:

    • Circular sizes from 21.3 OD x 3.2 - 508.0 OD x 16.0
    • Larger circular sizes from 508 up to and including 2134mm diameter are also available.
    • Square sizes from 40 x 40 x 2.5 - 400 x 400 x 16.0
    • Rectangular sizes from 50 x 30 x 3.2  - 500 x 300 x 16
    • Oval sizes from 150 x 75 x 4 - 500 x 250 x 16
    • 'Jumbo' sizes are also available on request : 350 x 350 x 19 - 800 x 800 x 60.
    • Most sizes can be made in lengths 6m - 14.5m, depending on the size and thickness
    • Length tolerance is +150mm /-0mm
    • Supplied self-colour
    • Supplied with plain ends unless otherwise specified
    • Celsius® is supplied with an inspection certificate to EN 10204 type 3.1
    • Celsius® is available on request in a variant with improved formability specifically for applications where tube ends are to be flattened

    Celsius® 355 elliptical sections

    The geometry of the elliptical sections, combined with its aesthetic appearance makes it an exciting section for architects to work with.

    Celsius® Ellipticals are manufactured to the same mechanical and dimensional requirements as  Celsius® 355 hot finished hollow sections, to a standard grade of EN10210 S355NH.  A true elliptical section with a 2:1 ratio of major to minor axes dimensions.   Sizes range from 150 x 75 x 4.0mm  to 500 x 250 x 16mm.

    Benefits of Celsius®  ellipticals

    • Enhanced aesthetics
    • High strength in bending with minimum shadow
    • High formability
    • Stress relieved
    • Low temperature suitability
    • Consistency of dimensions
    • Galvanisable
    • Weldable
    • Fully killed steel

    Applications

    Celsius® 355 ellipticals, are ideal for the following applications:

    • Structural columns
    • Glazing systems
    • Elegant structures
    • Lightweight structures

     

     

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    Properties

     

    Mechanical properties

    Yield strength Tensile strength Elongation % min Impact strength Carbon
    ReH min N/mm2 Rm min N/mm2 L0=3.65√So 10mm x 10xx equivalent
        specimen     (CEV) max
    Celsius® 420          
    T≤16mm T≤ 65mm T °C J  
    420 520-680 19 -20 40 0.45
    Celsius® 355          
    T≤16mm 3mm < T ≤ 100mm T °C J  
    355 470-630 22 -20 40 0.43

     

    Chemical composition

    % by mass

      C Si Mn P S Nb V Al total Ti Cr Ni Mo Cu N
      max max   max max max ma min max max max max max max
    Celsius® 420 0.2 0.6 1.00-1.70 0.035 0.030 0.050 0.20 0.020 0.03 0.30 0.80 0.10 0.70 0.03
    Celsius® 355 0.20 0.5 0.9-1.65 0.035 0.030 0.050 0.12 0.020 0.03 0.30 0.50 0.10 0.35 0.020

     

     

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    Dimensions

    Dimensional capability

    Celsius®420 and Celsius® 355 are available in:

    • Circular sizes from 21.3 OD x 3.2 - 508.0 OD x 16.0
    • Larger circular sizes from 508 up to and including 2134mm diameter are also available.
    • Square sizes from 40 x 40 x 2.5 - 400 x 400 x 16.0
    • Rectangular sizes from 50 x 30 x 3.2  - 500 x 300 x 16
    • Oval sizes from 150 x 75 x 4 - 500 x 250 x 16
    • 'Jumbo' sizes are also available on request : 350 x 350 x 19 - 800 x 800 x 60.
    • Most sizes can be made in lengths 6m - 14.5m, depending on the size and thickness
    • Length tolerance is +150mm /-0mm

    Further details of specific size and grade combaintions can be found in our Celsius downloads.

     

    Dimensional tolerances

    Dimensional tolerances are in accordance with EN10210: Part 2

      Circular/Ellipticals Square/Rectangular
    Outside dimension (D B and H) Circular ±1% with a min of ±0.5mm and maximum of ±10mm ±1% with a min of ±0.5mm
      Ellipticals ±1% with a min of ±0.5m  
    Thickness (T) -10% -10%
      Note: Positive deviation limited by mass tolerance Note: Positive deviation limited by mass tolerance
    Squareness of side - 90 degrees ±1 degree
    External corner profile - 2T max at each corner*
        (EN10210 has 3T max)
    Concavity/convexity (x) ±1% of the side, measured independently of
        the tolerance on the outside dimension
    Twist (V) Ellipticals: 2mm plus 0.5mm/m max 2mm plus 0.5mm/m max
      (The permitted tolerance is twice the value for H<250) Section is placed on a flat surface with one end
        held flat. At the other end the height difference of
        the two lower corners is taken
    Mass (M) ±6% on individual lengths ±6% on individual lengths
    Straightness Maximum 0.2% of the total length & 3mm over every  Maximum 0.2% of total length & 3mm over every 
      1m length  1m length
      Ellipticals: The permitted tolerance is twice the value for H<250  
    Length +150mm/-0mm +150mm/-0mm
    Out-of-roundness (O) Circular 2% for hollow sections having a diameter to thickness
      ratio not exceeding 100  




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    Downloads

     

    Celsius® 420

    Interactive brochure

    Further Celsius® 420 information and downloads can be found at www.tatasteelconstruction.com.

    Celsius® 355

    Celsius 355 Test Certification
    Celsius 355: The Ultimate Choice
    Celsius 355NH Technical Guides

    Hollow Sections: For structural and mechanical applications

      

    Technical Response Documents

    Here you will find a collection of technical response documents that refer to recent tubular technical developments and current industry topics.

    Celsius 355 NH explained (English)
    Celsius 355 NH explained (Deutsch)
    Celsius 355 NH explained (Nederlandse)
    Celsius 355 NH explained (Francais)

    Celsius 355 NH hot finished hollow section is manufactured exclusively from normalised, fine grain steel. This enables you to benefit from many advantages – in both performance and processing. Celsius 355 is supplied with an inspection certificate type 3.1. This guarantees that our products comply with European Standard EN10210. Until now, however, our product certification has not fully reflected the quality and traceability inherent in Celsius 355. Click here to read the new "Celsius 355 NH explained" booklet which guides you through the changes we have made to our certification in an easy to read question and answer format.

    Design of Welded Joints - Technical Interview (English)
    Design of Welded Joints - Technical Interview (Deutsch)
    Design of Welded Joints - Technical Interview (Francais)

    Tata Steel has produced free design aids for use with its hot-finished Celsius 355 structural hollow section. The aim is to help customers design tubular steel welded joints with ease and confidence. In our special Q&A feature, our technical expert in welded joints, Chris Morris, explains what’s on offer.

    Welded Joints Examples

    To provide further support when it comes to welded joints, we have created some examples that give typical solutions to a range of joint arrangements, including K-gap and overlap, KT-joints and joints with UB chords and hollow section bracings. Here are twelve simple examples showing full calculations and references to the Tata Steel welded joints design manual and EC3.

     


    back to top

    Overview

    Overview

    Celsius® 420 - Hot finished structural hollow sections

    Celsius® 420 is the next generation in hot-finished structural steel. A new steel grade yields greater strength of 420 MPa, requiring less welding, foundations and temporary structures onsite, and offers weight saving capabilities for more cost-effective construction.

    A choice of circular, square, rectangular and elliptical hollow sections can help specifiers meet a broad range of design requirements, while Celsius® 420’s tight corner radii exceeds industry standards to reduce the risk of fracture and deliver improved visual appeal.

    Celsius® 420 - Key product features

    • Normalised fine grain steel, so free of internal stresses and with a minimum strength of 420 MPa – allowing the highest fabrication factors and enabling material cost savings and lighter structures
    • Available in a wide range of circular, square, rectangular and elliptical hollow sections
    • Tight corner radii, exceeding the standard - enhancing the product’s aesthetic appeal whilst avoiding the risk of brittle fracture which occurs in some cold formed products
    • Dimensional consistency, high levels of formability and, because the steel is fully killed, excellent weldability
    • Certified as suitable for all structural applications, fully compliant with design codes and overcomes design risks associated with other forms of hollow sections
    • Certified as suitable for mechanical applications, especially those involving cyclic loading
    • Suitable for low temperature applications (40J @ -20°C)
    • Batch-tested to give the properties of the specific delivered material; full test certification supplied
    • Clearly marked as Celsius® 420, with the reassurance of batch traceability
    • Full technical support available
    • Excellent supply availability through approved stockholders
    • All Celsius® 420 material is CE marked and is fully compliant with the Construction Products Regulation
    • Suitable for galvanising with guaranteed silicon content between 0.15 and 0.25%
    • Guaranteed CEV 0.45 max compared to standard of 0.5 CEV.

    Celsius® 355 - Hot Finished Structural Hollow Sections

    Our Celsius® 355 product is the Ultimate Structural Hollow Section and is a hot finished product that offers a wide range of benefits. Made exclusively from normalised, fine grain steel with a yield strength of 355 N/mm2.

    Celsius® 355 is fully stress-relieved with uniform mechanical properties and manufactured to the standard grade EN 10210 S355 NH. Other grades, including those with improved impact qualities are available on request. 

    The strength and weldable qualities of Celsius® 355 mean that it can be used for all structural and mechanical applications, including multi-storey columns, space frames, lattice beams and frames for machinery and trailers.

    Celsius® 355 is available in:

    • Circular sizes from 21.3 OD x 3.2 - 508.0 OD x 16.0
    • Larger circular sizes from 508 up to and including 2134mm diameter are also available.
    • Square sizes from 40 x 40 x 2.5 - 400 x 400 x 16.0
    • Rectangular sizes from 50 x 30 x 3.2  - 500 x 300 x 16
    • Oval sizes from 150 x 75 x 4 - 500 x 250 x 16
    • 'Jumbo' sizes are also available on request : 350 x 350 x 19 - 800 x 800 x 60.
    • Most sizes can be made in lengths 6m - 14.5m, depending on the size and thickness
    • Length tolerance is +150mm /-0mm
    • Supplied self-colour
    • Supplied with plain ends unless otherwise specified
    • Celsius® is supplied with an inspection certificate to EN 10204 type 3.1
    • Celsius® is available on request in a variant with improved formability specifically for applications where tube ends are to be flattened

    Celsius® 355 elliptical sections

    The geometry of the elliptical sections, combined with its aesthetic appearance makes it an exciting section for architects to work with.

    Celsius® Ellipticals are manufactured to the same mechanical and dimensional requirements as  Celsius® 355 hot finished hollow sections, to a standard grade of EN10210 S355NH.  A true elliptical section with a 2:1 ratio of major to minor axes dimensions.   Sizes range from 150 x 75 x 4.0mm  to 500 x 250 x 16mm.

    Benefits of Celsius®  ellipticals

    • Enhanced aesthetics
    • High strength in bending with minimum shadow
    • High formability
    • Stress relieved
    • Low temperature suitability
    • Consistency of dimensions
    • Galvanisable
    • Weldable
    • Fully killed steel

    Applications

    Celsius® 355 ellipticals, are ideal for the following applications:

    • Structural columns
    • Glazing systems
    • Elegant structures
    • Lightweight structures

     

     

    back to top

    Properties

    Properties

     

    Mechanical properties

    Yield strength Tensile strength Elongation % min Impact strength Carbon
    ReH min N/mm2 Rm min N/mm2 L0=3.65√So 10mm x 10xx equivalent
        specimen     (CEV) max
    Celsius® 420          
    T≤16mm T≤ 65mm T °C J  
    420 520-680 19 -20 40 0.45
    Celsius® 355          
    T≤16mm 3mm < T ≤ 100mm T °C J  
    355 470-630 22 -20 40 0.43

     

    Chemical composition

    % by mass

      C Si Mn P S Nb V Al total Ti Cr Ni Mo Cu N
      max max   max max max ma min max max max max max max
    Celsius® 420 0.2 0.6 1.00-1.70 0.035 0.030 0.050 0.20 0.020 0.03 0.30 0.80 0.10 0.70 0.03
    Celsius® 355 0.20 0.5 0.9-1.65 0.035 0.030 0.050 0.12 0.020 0.03 0.30 0.50 0.10 0.35 0.020

     

     

    back to top

    Dimensions

    Dimensions

    Dimensional capability

    Celsius®420 and Celsius® 355 are available in:

    • Circular sizes from 21.3 OD x 3.2 - 508.0 OD x 16.0
    • Larger circular sizes from 508 up to and including 2134mm diameter are also available.
    • Square sizes from 40 x 40 x 2.5 - 400 x 400 x 16.0
    • Rectangular sizes from 50 x 30 x 3.2  - 500 x 300 x 16
    • Oval sizes from 150 x 75 x 4 - 500 x 250 x 16
    • 'Jumbo' sizes are also available on request : 350 x 350 x 19 - 800 x 800 x 60.
    • Most sizes can be made in lengths 6m - 14.5m, depending on the size and thickness
    • Length tolerance is +150mm /-0mm

    Further details of specific size and grade combaintions can be found in our Celsius downloads.

     

    Dimensional tolerances

    Dimensional tolerances are in accordance with EN10210: Part 2

      Circular/Ellipticals Square/Rectangular
    Outside dimension (D B and H) Circular ±1% with a min of ±0.5mm and maximum of ±10mm ±1% with a min of ±0.5mm
      Ellipticals ±1% with a min of ±0.5m  
    Thickness (T) -10% -10%
      Note: Positive deviation limited by mass tolerance Note: Positive deviation limited by mass tolerance
    Squareness of side - 90 degrees ±1 degree
    External corner profile - 2T max at each corner*
        (EN10210 has 3T max)
    Concavity/convexity (x) ±1% of the side, measured independently of
        the tolerance on the outside dimension
    Twist (V) Ellipticals: 2mm plus 0.5mm/m max 2mm plus 0.5mm/m max
      (The permitted tolerance is twice the value for H<250) Section is placed on a flat surface with one end
        held flat. At the other end the height difference of
        the two lower corners is taken
    Mass (M) ±6% on individual lengths ±6% on individual lengths
    Straightness Maximum 0.2% of the total length & 3mm over every  Maximum 0.2% of total length & 3mm over every 
      1m length  1m length
      Ellipticals: The permitted tolerance is twice the value for H<250  
    Length +150mm/-0mm +150mm/-0mm
    Out-of-roundness (O) Circular 2% for hollow sections having a diameter to thickness
      ratio not exceeding 100  




    back to top

    Downloads

    Downloads

     

    Celsius® 420

    Interactive brochure

    Further Celsius® 420 information and downloads can be found at www.tatasteelconstruction.com.

    Celsius® 355

    Celsius 355 Test Certification
    Celsius 355: The Ultimate Choice
    Celsius 355NH Technical Guides

    Hollow Sections: For structural and mechanical applications

      

    Technical Response Documents

    Here you will find a collection of technical response documents that refer to recent tubular technical developments and current industry topics.

    Celsius 355 NH explained (English)
    Celsius 355 NH explained (Deutsch)
    Celsius 355 NH explained (Nederlandse)
    Celsius 355 NH explained (Francais)

    Celsius 355 NH hot finished hollow section is manufactured exclusively from normalised, fine grain steel. This enables you to benefit from many advantages – in both performance and processing. Celsius 355 is supplied with an inspection certificate type 3.1. This guarantees that our products comply with European Standard EN10210. Until now, however, our product certification has not fully reflected the quality and traceability inherent in Celsius 355. Click here to read the new "Celsius 355 NH explained" booklet which guides you through the changes we have made to our certification in an easy to read question and answer format.

    Design of Welded Joints - Technical Interview (English)
    Design of Welded Joints - Technical Interview (Deutsch)
    Design of Welded Joints - Technical Interview (Francais)

    Tata Steel has produced free design aids for use with its hot-finished Celsius 355 structural hollow section. The aim is to help customers design tubular steel welded joints with ease and confidence. In our special Q&A feature, our technical expert in welded joints, Chris Morris, explains what’s on offer.

    Welded Joints Examples

    To provide further support when it comes to welded joints, we have created some examples that give typical solutions to a range of joint arrangements, including K-gap and overlap, KT-joints and joints with UB chords and hollow section bracings. Here are twelve simple examples showing full calculations and references to the Tata Steel welded joints design manual and EC3.

     


    back to top