How many grams weight for mm cartridge?

Hear we go again.....a cartridge is designed with the suspension, magnets, coils, et al being in a specific place for all to for these disparate parts to work at their best places and values to do their best work.  There is one and only one vtf that brings all of this together... The cartridge designed will give a range saying that no damage to the cartridge will result, or that there will be some tracking of the record at these extremes, however, the cartridge works best at the designers published optimal vtf.  I am a pro musician, and have always sought to apply standards to all I have/do.  I don't play Mozart in the style of Mahler, and don't track a cartridge at some quasi optimal vtf.

I don’t know guys where are you looking for Grace specs, but go on vinyl engine and check scan of the original grace manual for all models (except Ruby). There is a chart in comparison on page 2 for all of them with tracking force range from 0,5 to 2g for those top f9 models.

@chakster...there are actually (2) pdf’s on Vinyl Engine. The first one, (Farsch) says 1.2 grams across the board, except for the F9P which is 2.5 grams.

The second pdf, (Alec124c41) shows the .5 to 2.0 range.

http://www.vinylengine.com/library/grace/f9.shtml

I have the actual owners manual from the F9E cartridge box and it says 1.2 grams, no range. I also just checked my dealer binder for Grace and it also says 1.2 grams. I have a pdf of the actual owners manual I can send.

Not sure when Grace changed the info, but again, .5 grams is way loo light for the F9 series of carts.

Thank you so much for all those responded - you guys are a great source of intelligent info! 
  
  I don't know much about cartridges as you must have guessed.
I bought the Denon TT used and the guy said the cartridge is Shure V type that is pretty old design. I don't have manufacturer's recommendation so I will just leave it at 1.7 grams then - it sounded better than .5 grams.