What is Wheel Disk Size? i.e Low, Standard, High Disk

Im just trying to find out the exact meaning of wheel Disk sizing..

Is this the same as wheel X Factor? (distance between mounting surface and caliper)

So if a wheel has a Low Disk (stating 32mm), Standard Disk (stating 40mm) and a High Disk (stating 48mm)
Does this mean the clearance between the back face of the wheel to the mounting surface of the wheel? (Like back spacing?)

So for a Example,

I am ordering a new set of wheels, custom sizing, built to order,

I provide the company with, (e.g the wheel design is the same)
width
Size
offset
pcd
hub bore
and disk size

[IMG]http://i993.photobucket.com/albums/af53/OO521/Offset_and_size.jpg[/IMG]

The company told me they need my x factor not disk size.

If I measure my x factor and give them the details, will the size of the wheel be different to the the wheel I want?

As they are making a wheel with my specs but by clearance from the x factor not clearance by the disk size, (disk size maybe different to x factor size).

Anyone have any clue??

As Im lost!

Thanks.

I'm lost with you...

In australia somethings are worded differently.   Why not just ask what is the meaning of X Factor?      My guess is that is what they are looking after since looks like you gave them all the other specs needed.

Wheel disk size defines how much clearance a particular wheel allows for your brake caliper. The wheel disk "size" refers to how deep the faces hub is. Meaning, the distance from the back of the face of the wheel, to the mounting point of the wheels hub. The lower the number, the less brake caliper clearance you will have. You need to measure how far the outer most point on your brake caliper is from the wheel hub. This will tell you what face you have to run.

That sounds like back spacing?
Is Back spacing the same as Disk Size?

Back spacing is the "American" method of offset. Offset is measured from the center line of the wheel, to the face of the mounting hub of the wheel. Back spacing is measured from the very back of the wheel to the mounting hub of the wheel. Back spacing and offset are both ways of measuring how far out a wheel will stick out from the mounting point of the cars wheel hub.

pretty much what has already been said. different disk sizes are offered; some for big brake clearance, some for max lip, and some in between. brake clearance will be achieved either by having a thicker pad on the wheel or different face curvature.