from what i remember they are all steel.dulyebr said:
replace the rings with aluminium ones which are lighter than the standard XT or Titanium - 50g
all bolts aluminium....-20g
lightest possible would be to put some Extralite octaramp rings (109g for the set of 44/32/22). such a crankset would weigh 825g which is already pretty close to XTR. i have done this to some cranks shown below although the granny is a "heavy" 24t of a 5 bolt set and big rings Specialites TA....