This technical note reports the feature recognition test results using three systems: IF2, F-Rex and FBMach. Hint-based reasoning extends the portions of an object's boundary that are associated with a machining feature so as to create a material removal volume. Portions of the feature that are missing because of spatial intersections with others are reconstructed. Recognized features also provide useful information about accessibility and other machinability constraints. (C) 1999 Elsevier Science Ltd. All rights reserved.