The #400 Smooth Rolling Pin is used for everyday baking of pies, cookies, pizza and other crusts. the #420 Corrugated Rolling Pin is the most common rolling pin used for lefse, the reason for the grooves is to remove air pockets from the dough. The #440 Square Cut Rolling Pin is also used for potato lefse but most often used for Hardanger Lefse, these groves also help remove the air pockets from the dough. The #420 & #440 rolling pins can also be used for pies, cookies & pizza.