Front Brake Disc one or two fixing screws

[Numptysnumnuts]

I know there are two threaded fixing holes on these discs but both of mine only have one threaded torx / star bolt. Is this right or should there be another one.

http://s20.postimg.cc/cb3uuge7h/image.jpg

[boostjunky]

These are just to locate the disc with the wheel off the car, once you bolt the wheel on the disc will be secured in place so you should be able to get away with one.

[Denty120]

Mine don't have either screw in. As said they only locate the disc.