M1.6 thread size is not a catalog mistake. This is the correct size when listed in the catalog. If you are having trouble locating hardware, we also sell hexagonal socket head cap screws with a M1.6 thread (Misumi part numbers: CB1.6-5, CB1.6-8, CB1.6-10, CB1.6-11, and CB1.6-15, where the last number in the part number refers to the length).