documentclass{article}
usepackage{pgf,amsmath,tikz,type1cm,fix-cm}
usetikzlibrary{positioning}

newlength{XHeight}
newlength{XWidth}

newcommand*RF[3]{ensuremath{
      settowidth{XWidth}{#1}
      addtolength{XWidth}{.4em}
      setlength{XHeight}{XWidth}
      tikz[baseline]{
        draw
        (.75XWidth,.3XHeight) --
        (0.25XWidth,.3XHeight) --
        (.495XWidth,-0.1XHeight) --
        (.98XWidth,.7XHeight) --
        (1.5XWidth,.7XHeight) ;
        node at (0.5XWidth,.5XHeight)[scale=0.66] {$#1$};
        node at (1.25XWidth,.9XHeight)[scale=0.66] {$#2$};
        node at (1.25XWidth,.5XHeight)[scale=0.66] {$#3$};
      }
    }
}

begin{document}
test RF{3.2}{Mill}{Rz}test RF{0.8} {grinder}{}test\RF{0.8} {}{}test\
end{document}