Previous research has shown that the grain boundaries, i.e. the boundaries between the reactive maceral derived components (RMDC) and inertinite maceral derived components (IMDC), are one of the major sources of weakness in metallurgical coke. To address this fundamental research problem, we have applied a combination of two techniques; (i) fractography and (ii) tribology, as novel approaches to assess the strength and properties of the interfaces in coke. We have used fractography to analyse fractured coke surfaces to identify and quantify the sources of microstructural weakness and modes of fracture propagation, e.g. propagation through or around IMDC. The different mechanisms of fracture growth indicate the strength of the grain boundaries in coke. Tribology can successfully distinguish between IMDC that are ‘hard’ and ‘soft’ as well as those that are weakly/strongly bound to the RMDC. This demonstrates the potential to improve predictions of coke strength from coal properties. The mechanisms of wear in metallurgical coke, e.g. abrasive and adhesive wear, have been identified, and linked to the mechanisms of coke degradation in the blast furnace. The wear properties of the distinct textural constituents present have also been established. Through application of advanced surface characterisation techniques we anticipate it being possible to improve current understanding of the chemical interactions occurring between different textural constituents. It may also be possible to predict the type of inert interface that will be created in coke from its properties in the original coal.