This reference identifies the Hybox 355 square hollow section (SHS) listed as 300x300x12.5. It brings the principal dimensional and mass information together with the applicable European standard reference, helping engineers, detailers, estimators, and CAD users interpret the section listing consistently.
Use this page alongside the site’s SHS terminology guide, steel section properties reference, and EN 10219 overview when checking section designations, fabrication information, or drawing data.
Hybox 355 SHS 300x300x12.5
Hybox 355 Square Hollow Sections
refer to : EN 10219-2:2006-04
the European standard that specifies tolerances, dimensions, and sectional properties for cold-formed welded structural hollow sections made of non-alloy and fine grain steels. It complements EN 10219-1, which covers technical delivery conditions.
Dimension : 300x300x12.5
Depth : 300 mm
Width : 300 mm
Thickness : 12.5 mm
Outer Corner Radius : 37.5 mm
Inner Corner Radius : 25 mm
Sectional Area : 137 cm2
Unit Weight : 107.5 kg/m
How to read this SHS reference
The designation describes a square hollow section with equal listed depth and width and a specified wall thickness. Unlike a solid square bar, an SHS has a hollow interior and formed corners. The listed outer and inner corner radii are therefore important when interpreting the section geometry in design models, connection details, and CAD drawings.
Sectional area and unit weight
Sectional area describes the area of steel in a cross-section. It is used as a basic input for calculations and quantity checks, but it is not a complete set of section properties. Engineers may also need properties such as the relevant second moments of area, section moduli, or radii of gyration from an appropriate verified reference when performing design checks.
Unit weight expresses the listed mass per unit length. It is useful for estimating member dead load, handling requirements, transport quantities, and material takeoffs. Project calculations should use the governing specification, fabrication information, and approved design data rather than relying on a catalog entry alone.
Standard and drafting context
The source identifies EN 10219-2:2006-04 for tolerances, dimensions, and sectional properties of cold-formed welded structural hollow sections, while EN 10219-1 is identified as covering technical delivery conditions. These references serve different purposes, so specification review should confirm which requirements apply to the procurement and project documentation.
The linked DWG resource can support preliminary detailing and drawing coordination. Before issuing fabrication or construction documents, verify the geometry, units, layer conventions, material designation, connection details, and project-specific requirements against the approved source information.
Frequently asked questions
What does SHS mean?
SHS means square hollow section. It is a hollow structural steel profile with square outside dimensions and formed corners.
What does 300x300x12.5 identify?
In this listing, the designation identifies the section’s listed depth, width, and thickness. The source gives the depth and width as 300 mm and the thickness as 12.5 mm.
Why are both outer and inner corner radii listed?
The two radii describe the formed corner geometry at the outside and inside of the section. They can matter when modeling the profile, checking clearances, or preparing connection and fabrication details.
What is the difference between sectional area and unit weight?
Sectional area describes the amount of steel in the cross-section, while unit weight describes the listed mass for a length of the member. They support different types of design and estimating checks.
What is the EN 10219 reference used for?
The source identifies EN 10219-2:2006-04 in connection with dimensions, tolerances, and sectional properties for cold-formed welded structural hollow sections. It also distinguishes EN 10219-1 as the reference for technical delivery conditions.
Can the DWG be used directly for fabrication?
The DWG is a drafting reference. Review its geometry and drawing setup against the approved project requirements and verified manufacturer or supplier information before using it for fabrication documentation.
