The temperature that you should blanch fries at is 176 F.
When blanching the fries don't let the temperature of the water get below 176 F and blanch the fries for 14 to 15 minutes in the water.
Then drain the fries on a cooling rack and then fry them at 338 F until they form a crust but are still blond.
After that's done then you fry them again at 374 F until they are crispy and become golden brown.
That will make some nice tasty french fries that will turn out just like the fast food french fries you buy.
I started blanching fries and they are much better than just frying the fries directly.