I'm not sure if I understand the question. What is the context of the IJK? Is it being used as a machining (CNC) vector or a CMM vector? Or a localized position point?
If it's for multi-axis CNC vectors there is no IJK "tolerance" applied beyond the machine's limitations. The design engineer may use degrees and fractions of a degree to specify the vector of a hole, for example, but it's up to the CNC programmer (and his software) to translate that to the machine's code of IJK vectors, with foreknowledge of the machine's limitations.
If your question is relative to CMM, I'm afraid my knowledge of that stuff is 20 years out of date. In my time, CMM IJK's were just a convenience to get somewhere on a part where a vertical probe couldn't go.
Here's an interesting definition I ran across though, from Geomet:
Vector Points
- Surface 3D Points. Compensated by one probe radius
along the defined IJK surface vector.
Hope this helps. I didn't know you can comp the radius by using the vector. I'm kinda presuming this is independent of the probe centerline.
