Home | Resources | Specification | BSF High Load Connectors Specification

BSF Beam and Column Connectors Specification

Traditionally, concrete beams were supported on columns using integral corbels. Apart from being difficult and costly to form in the column, they reduce headroom locally and spoil the appearance.

Using BSF connectors eliminates the need for corbels, leaving a smooth soffit. Round, or odd-shaped columns present no problems. For heavy loads from beams into columns, walls or other beams, the BSF system should be used. They consist of three-part telescopic connectors, but are otherwise similar in application principle to the range of telescopic stair landing connectors.

BSF BB (beam to beam) and BSF BC (beam to column) connectors are designed for heavy-duty beam supports, with capacities from 225–1100kN. By using pairs of connectors, loads up to 1400kN can be catered for.

Product reference

  • [BSF 225] – Capacity: 225kN.
  • [BSF 300] – Capacity: 300kN.
  • [BSF 450] – Capacity: 450kN.
  • [BSF 700] – Capacity: 700kN.
  • [BSF 1100] – Capacity: 1100kN.

Steel finish

  • Plain.

 

Guidance for BSF Beam Connectors

  • As standard.

Material

  • Steel (grade S355, minimum).

 

Concrete strength class

  • C35/45, minimum.

 

Reaction to fire

  • Class A1, according to EN 13501-1.

There’s no drilling, which of course involves manpower. And every drilling detail comes with resin, which is not cheap. The safety hazard of silica dust is an important consideration. Eliminating all of this gives the contractor a great advantage.

Florin Rotariou, Senior Engineer, Keltbray 
Florin Rotariou, Senior Engineer, Keltbray

Telescopic connectors provide us numerous advantages for precast stair installation. Apart from improved time and efficiency, the health and safety gains over traditional support methods are a key driver to satisfy our own needs, as well as those of our clients.

Shane Dunleavy, Project Manager, Morrisroe 
Shane Dunleavy, Project Manager, Morrisroe

Thank you for sending the calculations and installation advice. The new calculation software looks great. Very clear, user friendly and with more design checks than the previous version. It’s a pleasure to see how you are constantly improving.

Stefan Pauceanu, Senior Structural Engineer, Ground Construction Ltd 
Stefan Pauceanu, Senior Structural Engineer, Ground Construction Ltd

As specialists in precast concrete car park construction, we use telescopic connectors for many key applications. Particularly, the BSF system helps us to construct a ‘modern’ frame without cumbersome corbel supports and enables rapid assembly on site. The technical back-up provided by Invisible Connections provides us with added reassurance.

Peter Crofts, Precast Design Manager, SCC Design Build Ltd 
Peter Crofts, Precast Design Manager, SCC Design Build Ltd

  ​   

 

  

  

© 2026 Invisible Connections Ltd | All Rights Reserved | Privacy Policy | Cookies

Invisible Connections, FERBOX and REDiBOX are registered trademarks