this may seem like a stupid question, but i experience great difficulty in getting the last bit of the tire to snap into the rim when i change tires

i am not able to completely force the bead of the tire into the rim with my hands; i generally try to use a tire lever to force the final bit of tire into the rim, but the tire levers tend to snap when i do this (this gives an impression of the amount of resistance i am encountering); since all my levers have broken, i have resorted to using the blade of a screwdriver or hammer to force it on (fortunately hammers don't break too easily)

can anyone offer any suggestions on how to approach this problem? should i consider buying a tire from a different manufacturer that might not fit quite so tightly? the amount of force required to seat the last bit of tire into the rim seems quite remarkable to me..

anyways, thanks in advance for your help