$5.$ Broach design requires careful consideration of the $\_\_\_$ to ensure efficient material removal.

$6.$ Milling cutters are classified by their $\_\_\_$ profiles, which determine the shape of the cut they produce.

$7.$ The flute design in a drill bit for milling affects the tool's $\_\_\_$ and chip removal efficiency.

$8.$ A twist drill's $\_\_\_$ angle influences its cutting efficiency and the quality of the hole.