Roller milled flour is flour produced by passing grain between pairs of steel rollers set close together and rotating at slightly different speeds, so the grain is sheared and crushed rather than pounded. Modern flour milling is built on this principle: break rolls open the kernel and scrape endosperm from bran, then reduction rolls progressively grind the purified middlings to fine flour, with sifting between each pass. The differential speed creates the shearing action that strips endosperm cleanly while keeping bran flakes large enough to sift out. Compared with stone milling, roller milling runs cooler at each pass, gives precise control over extraction rate and particle size, and produces the white, fine flour that industrial baking demands.