4) What are the ranges of morse tapers used on taper shank twist drills, reamers and lathe centres?

5) What type of standard taper used on external taper of lathe spindle nose?

6) What is the included angle of metric acme thread?

7) What is the taper ratio for a taper length of 20 units the difference in diameter is one unit?

8) Which taper is most commonly used as standard taper in industries?