Internal Solid Wall Steel Lintels

Stressline internal solid wall steel lintels are galvanised steel ‘box’ type lintels designed for internal walls of 75mm to 150mm in width. HD (heavy duty) and XHD (extra heavy duty) versions are available as well as the less expensive LD (light duty) versions.

Box lintels are easy to install and the SL100 and SL140 versions have the option of an added ‘internal panel’ for longer lengths. This type of lintel is very versatile and can be used for a number of applications. Please see our steel lintel load tables for more information.

Our internal or ‘box’ lintels are available at various lengths starting at 600mm. Some box lintels can be manufactured to 5100mm. For more information on internal solid wall steel lintel sizes and prices please download the brochure section below. For the full brochure you can download it from our downloads page.

Stressline internal solid wall steel lintel


Stressline internal solid wall steel lintels are designed to support:

  • Concrete floor loads
  • Masonry loads, timber floor joists and/or roof trusses
  • Attic truss loads
  • Point loads (compound trusses, steel beams)

Internal solid wall lintels are designed for 75mm, 100mm or 140-150mm wide, non-load bearing and load-bearing walls.


Internal solid wall lintels and box lintels are very versatile. They can be supplied insulated for use at eaves level.

They have a build in plaster key – perforated plate to base and two sides.

They are also suitable for use under various loading conditions.

To download our standard leaf steel lintel load span tables, please click the button below. This brochure section has details of our standard steel lintels only. To download the full brochure, please navigate to our downloads page. For more information on our standard concrete prices, please contact your local ASM – you can see who that is on our ‘who to contact’ page or email us directly.

Internal solid wall steel lintel load span tables