Geometrical control of eddy currents in additively manufactured Fe-Si

•Simulations shown to match experimental losses in solid cross-section of Fe-6.5 wt%Si.•Air gaps in the cross section are used to improve eddy current losses , introducing a novel hexagonal cross section.•Experimental samples underperform when compared to simulated losses.•XCT shows reduced electrical short-circuiting from 27% to 0.5%, bringing sample losses closer to simulated values.