Mechanical Engineering - Production Engineering - Discussion
Discussion Forum : Production Engineering - Section 1 (Q.No. 45)
45.
If the helix angle of the drill is made __________ 30°, then the torque required to drive the drill at a given feed will be more.
Discussion:
6 comments Page 1 of 1.
Shekhar said:
8 years ago
For drills Max helix angle is rake angle.
If we decrease the helix it lowers the rake also.
Low rake means shrpness of the tool less.
Less sharpness of the tool leads to more torque requirement.
If we decrease the helix it lowers the rake also.
Low rake means shrpness of the tool less.
Less sharpness of the tool leads to more torque requirement.
(3)
Chiru said:
1 decade ago
Torque required for drill bit reduces with increasing helix angle. But increasing helix angle decreases flute are to disposal of chips. So optimum helix angle is 30 degree.
(1)
Chetan said:
1 decade ago
Can any one explain this?
Gaurav verma said:
1 decade ago
Aluminum 32 to 48,
Brass 0 To 20,
Cast iron 24 to 32,
Mild steel 24 to 32.
Stainless steel 24 to 32,
Plastics 0 to 20.
Brass 0 To 20,
Cast iron 24 to 32,
Mild steel 24 to 32.
Stainless steel 24 to 32,
Plastics 0 to 20.
Banty said:
1 decade ago
Usually 30 degree is used and below 30 for brass and above 30 for Al. Answer is right.
Yatharth said:
9 years ago
Due to difficulties in forming the thread, helix angle greater than 30 degree are rarely used. Moreover, above 30 degree the friction angle becomes smaller than the helix angle and the nut is no longer self-locking and the mechanical advantage disappears.
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