There generally seems some difficulty with spindle bars not fitting either lock or handles, I think a lot of it is down to metrication. Most handles and locks particularly those produced abroad seem to come with 8x8mm square bars whilst imperial ones tended to be 5/16" square. Although the difference is a "midges dick" difference and most locks and handles usually are a sloppy fit that can cope with either, I have come across latches where one will fit and not the other.

Richard