The chemical compatibility of an YSiAlON cutting tool and a number of experimental SiAlON ceramics with iron-based alloys (binary alloys, steels and grey cast iron) is studied by means of static metal-ceramic interaction couples in vacuum in the temperature range 1000-1200 degrees C, with holding times long enough to be able to characterise the interaction layers. The metal-ceramic interaction is modelled and the influence of the ceramic and iron-based alloy composition on the reactivity is investigated. Furthermore, the relative tool wear of the ceramics when turning steel is compared with the predicted mechanical wear by abrasion, calculated from the mechanical properties of the ceramics, and the predicted chemical wear, estimated from equilibrium solubility calculations in pure iron. The relative crater and flank wear of the ceramics correlates well with the predicted chemical wear. The results of the interaction couples and the turning tests are compared.