Graham flour is a coarse-ground un-sifted wheat flour. This flour is high in fiber and more nutritious than processed wheat flour.
Graham flour can be purchased but I prefer to DIY it. So to make Graham flour you will need wheat kernels and a grain grinder.
I purchased 50 lbs of hard red wheat kernels from https://centralmilling.com/product/organic-whole-hard-red-winter-wheat/ (I’m not an affiliate)
My choice in grinders is the Wondermill https://thewondermill.com/ (I’m not an affiliate)
To make the flour I put the grinder on the coarse setting. That’s it. It’s that easy. 5 pounds of kernels gave me 4 quarts of flour.