New Find on My Rotor to Hub Connection

[KJRGT]

I had my wheels off today, cleaning everything up from running at Auto Club Speedway in Fontana last weekend when I noticed something for the first time and cannot figure out why it is. :confused
There are 5 holes drilled in the hat part of the brake rotors on the same surface that is also cut with 5 holes for the lug nut studs that poke through from the wheel hub. Only 3 of these non lug stud holes have "brake disc retainer screws" through them attaching the rotor to the hub.
Since the other two holes on each rotor do not align to a threaded hole in the wheel hub, I assume this is correct, and only 3 retainer screws are shown in my 2005 manual.
So.......why drill 5 holes? Or better yet, why not use 5 retainer screws to attach the rotor to the hub instead of only 3?

 

[BlackICE]

The screws holding the rotors to the hub are not really needed. IMO they are they to retain the rotors on the car while the wheels and calipers may be off during the manufacturing process. The extra holes just speed up the process of inserting the screws.

 

[Shadowman]

The screws holding the rotors to the hub are not really needed. IMO they are they to retain the rotors on the car while the wheels and calipers may be off during the manufacturing process. The extra holes just speed up the process of inserting the screws.

You were quick to the table.......

Shadowman

 

[64c2vette]

Past related discussion http://www.fordgtforum.com/forums/showthread.php?t=741&highlight=wheels

 

[KJRGT]

Thanks Fellas....