Technical Guidance Note (Level 2, No. 17): Simple connections in steel frames

The most common type of connection within steel-framed structures is the 'simple connection'. It is often described in the form of a pin that is designed to support shear and tie forces, but not bending moment forces. This is a simplification of the actual condition as, in the vast majority of cases, even simple connections do transmit some bending moments through to the elements they are fixed to. This Technical Guidance Note aims to clarify what a simple connection is by explaining its use when designing connections within steel frames. Additionally, guidance is offered on the different types of simple connections that are used and what design checks need to be carried out. The design of simple connections is not covered in detail, due principally to the large number of checks needed for any connection type. Instead, references are provided to codes of practice and authoritative texts with guidance on how these checks can be carried out.