A single point thread cutting tool should ideally have
A. Zero rake angle
B. Positive rake angle
C. Negative rake angle
D. Point angle
Answer: Option A
Solution (By Examveda Team)
The correct option is "Zero rake angle" (Option A).Reason: In thread cutting, accuracy of the thread form is critical. A zero rake angle preserves the true geometry of the thread profile and avoids distortion during cutting.
Why not positive rake? Although it reduces cutting forces in general machining, it changes the effective cutting geometry in threading and can distort the thread form.
Why not negative rake? It increases cutting forces and is unnecessary for precision thread cutting, potentially harming surface finish and tool life.
About point angle: The point (included) angle defines thread geometry (e.g., 60° for metric/UN), but it is a different parameter and not the ideal rake requirement.
Conclusion: For single point thread cutting tools, use zero rake angle to maintain accurate thread profile and dimensional correctness.
This Question Belongs to Mechanical Engineering >> Manufacturing And Production Technology
A
Positive rake angle: It is used when there is requirement of less cutting force and used for low strength materials like mild steel etc.
Negative rake angle: It is used for hard metals which requires high cutting force and machined at very high speed.
positiverake
Zero rake angle: It is used for gear cutting or thread manufacturing. Brass and cast iron are machined with zero rake.
Threading is done by a form tool. The forms tool ideally have zero rake angle
Positive rake angle is correct
Zero rake angle: It is used for gear cutting or thread manufacturing. Brass and cast iron are machined with zero rake.
Threading is done by a form tool. The forms tool ideally have zero rake angle.
Positive rake angle is required for thread cutting
B is correct