Table shows the ANOVA results for thrust force generation in CF/PEKK and CF/epoxy respectively. It is clearly evident that for both composites, feed rate is the most influential factor on the thrust force (96.10% contribution for CF/PEKK and 98.72% for CF/epoxy). In comparison, the impact of spindle speed on the thrust force is much lower (1.99% for CF/PEKK vs. 0.92% for CF/epoxy). The second order terms of Ff,, S and their interaction ( Ff S) have negligible influence on the resulting thrust force, with p values > 0.05 being statistically insignificant. The ANOVA results for CF/epoxy drilling showed good consistency with previous studies , where the feed rate is the most influential factor on thrust force (contribution >85%) while the contribution from the spindle speed was significantly lower (<5%). Despite the vastly different properties of CF/PEKK and CF/epoxy, the contribution of feed rate and spindle speed on the resulting thrust force appear to be at a similar level.