In article ,
digitect wrote:

If you use a screw with a known pitch, you can calculate the exact
amount of movement ("lead") each turn or portion will produce. The
common example is a 10-32 scew--each turn produces 1/32"(0.3125")
movement. So an eighth of a turn is 1/256" (0.0039"), a very fine
adjustment indeed. Mark the screw head and use a paper marking circle
with 10 degree increments to keep track of even more precise fractions
of turns. 11.52 degrees equals 0.001" although that won't divide a
circle evenly.

I've got a fence for my router table I made like that. If you use a 1/4-20
bolt, the numbers work out easier. 1/5th of a turn is 0.01 inches, and
with a little care, you can make 0.001 adjustments, which more than
qualifies as an RCH when working with wood.

Compress a spring under the bolt head when you assemble it to reduce
backlash.