CNC Cutting Tool Geometry & Selection 2

Question 1

What does a negative rake angle on a cutting tool indicate?

Accepted Answer

The cutting edge is angled away from the workpiece surface

Answer

A negative rake angle means the tool face tilts away from the direction of cut, which strengthens the cutting edge and is suited for hard or interrupted cuts.

Question 2

Which tool material is best suited for high-speed machining of cast iron without coolant?

Accepted Answer

Ceramic

Answer

Ceramic inserts withstand very high temperatures and are ideal for dry, high-speed machining of cast iron due to their thermal stability.

Question 3

The nose radius of a turning insert primarily affects which machining outcome?

Accepted Answer

Surface finish quality

Answer

A larger nose radius produces a smoother surface finish by spreading the cutting contact over a wider area.

Question 4

What is the purpose of a chip breaker groove on an insert?

Accepted Answer

Curl and break chips to prevent long stringy chips

Answer

Chip breaker grooves deform the chip as it forms, curling it into manageable pieces that clear the cutting zone safely.

Question 5

When turning stainless steel, which insert grade characteristic is most important?

Accepted Answer

High toughness and built-up edge resistance

Answer

Stainless steel is tough and work-hardens, so inserts need toughness and coatings that resist built-up edge (BUE) formation.

(CNC) Computer Numerical Control Machinist Technical Practice Test

(CNC) Computer Numerical Control Machinist Technical Practice Test

CNC Cutting Tool Geometry & Selection 2