The biggest part of the hand is the palm named WristlargeV3.

On this part there are 2 squary "holes" or "slots" that are intended to receive a nut.
Gael added this improvement after I suggested it one year ago at the beginning of the InMoov's project.

Since then I never checked the design but user Balse did and discovered that the slots can't receive a standard M8 nut. I checked it and he is right : the slots are too small and the design isn't adapted to a standard M8.

Slots are not adapted to a standard M8 nut

So I modified the slots.
They should now be able to receive a standard ISO M8 nut.

The new WristlargeV3_M8 has been added to the download "corrected parts" page.

Thanks Balse for reporting this !

UPDATED November 20th 2013

Balse downloaded the part and printed it.
Here is a photo he sent me of the print which confirms that the M8 nuts are now able to fit in the slots.
Thanks body !

Balse's printed version with standard M8 nuts