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Slow crack growth parameters for SiC-based filaments. τ is the lifetime, σ app the stress, n f the stress exponent and Ea τ the apparent activation energy describing the Arrhenius evolution of the environment constant A with temperature. [Display omitted] • Modified time to failure prediction expression applied to various SiC-based fibers. • Stress exponent subjected to a scale effect, induced by fiber misalignment. • Estimates for SCG parameters of SiC-based filaments. • Stress-probability time diagrams construction from simulation output. • Correlation between stress exponent and chemical composition (O and H content). The delayed failure of SiC fibrous reinforcement has continuously been investigated to warrant the long term performances of Ceramic Matrix Composite (CMC). Chiefly assessed on multifilament tow samples to alleviate some handling difficulties, subcritical crack growth (SCG) parameters are however ruled by structural artifacts which hinder the identification of intrinsic filament behavior. In this paper, we propose to estimate the true filament parameters for 5 fiber types from bundle behavior using a recently communicated Monte Carlo algorithm integrating flaw and stress distributions through a deterministic fracture mechanics law under Paris' formulation. So computed tow lifetime are broadly dispersed, encompassing raw data, and show a structure-dependent scale effect, revealed by n filament >n tow where n is the stress exponent. The relationship between SCG coefficient and chemical composition of the substrate is discussed and highlights the major effect of doping elements (Ti or Zr), oxygen or hydrogen content. [ABSTRACT FROM AUTHOR]