Morse taper reamer (Figure H-120), with straight or helical flutes, are used to finish reamtapered holes in drill sockets, sleeves,and machinetool spindle. Helical taper pin reamers (Figure H-121) are especially suitable for machine reaming of taper pin holes. There is no packing of chips in the flutes, as the chips are pushed forward through the hole during the reaming operation,which reduces the possibility of breakage. These reamers have a free-cutting actionthat produces a good finish at high cutting speeds. Taper pin reamers have a taper of 1/4 in. per foot of length and are manufactured in 18 different sizes ranging from smallest number 8/0 (eight naught) to the largest at number 10.