Identify HQ or Commodore Discs

[BlackBedford]

G'day

I have been trying to figure out the difference between the two types and found this:

Holden HQ - 7/16" UNF studs - 5 Studs - PCD 120.6mm - 72mm from stud to stud
Commodore - 7/16" UNF studs - 5 Studs - PCD 120mm - 72mm from stud to stud

So has anyone got a solution to tell the difference?

[BlackBedford]

Here I am talking to myself again.

The great Lord Google has found an answer from http://holdenpaedia.oldholden.com/Stud_Patterns :

What PCD do I have? The calculation for any five stud P.C.D. is from the centers of two of the closest studs divided by 0.58778 pretty hard to do by eye as Commodore an HQ are close, but if you have a vernier and measure from the outside of one stud to the inside of the next one is pretty accurate. To accurately measure your PCD. for 5 stud pattern. (in metric) measure as accurately as you can the distance between the centre of one stud to the center of the next closest stud, and then using a calculater divide that measurement by 0.58778 to attain your PCD. Be carefull to measure as accurately as you can because, for example, HQ is (close to 71mm) 70.915657 divided by 0.58778 = 120.65 (4.75") PCD. Commodore is (close to 70.5mm) 70.5336 divided by 0.58778 = 120.00 (4.724") PCD. To go from metric to imperial divide by 25.4.

[Warren]

Thanks Chris

Great info

Warren