The focused cutting fluid supply on the rake face of cutting tools has proven its positive impact on tool wear and chip formation in many machining processes. However, the realization of internal coolant channels in indexable milling cutters is difficult. Traditionally manufactured milling tools feature drilled coolant channels. Hence, the channels are restricted to being straight holes with intersections. In this paper, an additively manufactured tool with improved coolant channels was compared to a conventional tool when machining AISI 4140+QT. The additive tool resulted in lower tool wear and different vibration behavior compared to the conventional tool.