Is the rolex 3156 more anti-magnetic compared to 3186?

[timuS]

Hi everyone,

I encountered upon some rolex part-sheets online and found something interesting. The day-date caliber 3156's pallet fork no. is 3131-421, which is the same as the pallet fork no. of milgauss caliber 3131. And we know the milgauss pallet fork is made from an non-magnetic amorphous nickel-phosphorous alloy.

When you look at the GMT 2C 3186 caliber's pallet fork, it has a part no. 3135-421. Clearly this is not the same as the milgauss pallet fork.

Thus, does this mean that the 3156 day-date is more anti-magnetic compared to the 3186 GMT 2C?

How important is the pallet fork when trying to make the watch anti-magnetic? (I always thought an amagnetic hair-spring was enough )

Thanks in advance!

sumit