depth of cut

cutting speed

feed

all of these

number of pieces machined between tool sharpening

time the tool is in contact with the job

volume of material removal between tool sharpening

all of the above

independent of

dependent upon

feed rate, depth of cut, cutting speed

depth of cut, cutting speed, feed rate

cutting speed, feed rate, depth of cut

feed rate, cutting speed, depth of cut

grain size of the metal is large

grain size of the metal is small

hard constituents are present in the microstructure of the tool material

none of the above