Maker Case question

For those that have used the Maker Case program before:

First time using it and making a finger joint box. I inputted to makercase that my material thickness is .50”. But the depth of the joint in their outputted svg is .475”. Is that on purpose?….Or should I be reducing their line size to .001”? Just noticed it defaults to .01”.

Figured it out. When you select 1/2” material thickness but its really .472”. Have to manually define your material thickness if you really want .50”.