It is shown that manufacturing tolerances of the fiber parameters bend radius and numerical aperture (NA) significantly influence the fiber bend loss performance and spectral response of a fiber based edge filter. A theoretical model, validated by experimental results, is used to determine the changes in key spectral parameters for an edge filter, resulting from changes within their manufacturing tolerance range, for both the bend radius and NA. Finally, it is shown that bend-radius tuning during fabrication of such filters is a means of mitigating the effect of manufacturing variations.