A paper published in the October 2026 issue of Additive Manufacturing journal: The LPBF process generates complex thermal gradients and residual stresses during AlSi10Mg manufacturing. This study systematically evaluates the effect of residual stress on fatigue crack growth rates. The study used two sets of LPBF process parameters known to produce high and low residual stresses, measuring crack growth in the Paris region and near-threshold region using compact tension specimens at a load ratio of 0.1. Residual stresses were determined by neutron diffraction, the cut-compliance method, and the online compliance method. Results show that: the compressive residual stress at the center of 'high-stress' as-built parts leads to a higher crack closure level and a higher fatigue threshold, outperforming 'low-stress' as-built parts and annealed 'stress-free' samples. After correcting for crack closure and crack-tip residual stress, the crack growth data for all groups essentially converge onto a single curve—the differences in crack closure levels can explain most of the fatigue performance differences between as-built and annealed samples in both orientations. Value to powder buyers: ① The study provides a basis for selecting low-residual-stress LPBF process parameters, which can reduce the scatter in fatigue performance of as-built AlSi10Mg; ② The parameter window and powder characteristics jointly determine fatigue performance, and high-quality aluminum powder suppliers can leverage process synergy to endorse product consistency.