Have some THK HSR-15 blocks (HSR15A1SS & HSR15R1SS) as well as some supposed 15-series THK rails. The rails are different lengths, and I'm pretty sure they're chopped up from longer rails, but they're the same dimensions otherwise.
The blocks don't seem to fit on the rails. The problem area seems to be the narrow part of the setup, below the bearing ways. I know they recommend a special jig to get them on, but the narrower parts of the block are 10.40mm, while the narrow section of the rail is 11.00mm (0.6mm too big). All other dims seem fine. Unless the whole metal body of the block itself is meant to expand when loaded on, I don't see how they would fit.
While I could find all the spec sheets on THK's website for the blocks themselves, I couldn't find a single spec for the rails at all, aside from length.
Is something mismatched here?