The thread on the screw is a machine type and should be M3 gauge thread.
If you mean it will not screw in to the laptop, if you took it apart it is because two types of the threaded end are used the 5mm and a 7mm, or 8mm are most commonly used.
The longer thread ones are used for in a lot of laptops for screwing the open and close hinge brackets of the Lcd screen of the laptop to the Base of the laptop housing or surrounding case.
Two types are used for doing this on most hinges the 8mm in length ones are used on the metal part of the lower hinge support along with 5mm to 6 mm in length ones for extra support it matters where you place each of the screws in relation two the two holes provided on both sides of the hinge if it screws...