Millwork for a grain mill

A grain mill for performing a grain milling operation, comprising:

• a stationary lower support having a first screw thread;
• an upper support mounted on said lower support for vertical adjustment relative thereto, said upper support being non-rotatable relative to said lower support during such vertical adjustment and during a grain milling operation, said upper and lower supports forming a chamber, said upper support including a second screw thread having an opposite twist with respect to said first screw thread, said first and second screw threads having a common center axis;
• an upper mill stone affixed to said upper support and situated in said chamber;
• a lower mill stone disposed in said chamber beneath said upper mill stone for forming a gap therebetween, a height of said gap being variable by vertical adjustment of said upper support, said lower mill stone being driven about said axis during a grinding procedure;
• an adjustment ring having third and fourth screw threads joined to said first and second screw threads, respectively;
• and
• an adjusting device for rotating said adjustment ring about said axis relative to said upper and lower supports to vertically adjust said upper support in the absence of rotation thereof.