Celsius hollow sections
Overview
Manual
CELSIUS
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
Properties
Manual
CELSIUS
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 max 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

 

Dimensions
Manual
CELSIUS
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 combinations 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