CNC Cutting Tool Geometry & Selection 3

Question 1

What does ISO insert designation 'C' in the shape position indicate?

Accepted Answer

80-degree diamond shape

Answer

In the ISO insert identification system, 'C' designates an 80-degree rhombic (diamond) insert shape.

Question 2

Which coating is most commonly applied to carbide inserts to improve wear resistance at high temperatures?

Accepted Answer

Titanium Aluminum Nitride (TiAlN)

Answer

TiAlN coatings have excellent oxidation resistance at elevated temperatures, making them the preferred choice for high-speed dry cutting.

Question 3

What is the relief angle (clearance angle) on a cutting tool designed to prevent?

Accepted Answer

Rubbing of the tool flank against the machined surface

Answer

The relief angle provides clearance between the tool flank and the workpiece, preventing the tool body from rubbing against the just-machined surface.

Question 4

A drill with a 118-degree point angle is considered standard. A 135-degree point angle is used for:

Accepted Answer

Hard materials and self-centering applications

Answer

The 135-degree split-point drill is designed for harder materials and provides better self-centering without a center punch.

Question 5

Which cutting tool material has the highest hardness but lowest toughness?

Accepted Answer

Polycrystalline Diamond (PCD)

Answer

PCD is the hardest cutting tool material but is very brittle and requires vibration-free conditions to avoid fracture.

(CNC) Computer Numerical Control Machinist Technical Practice Test

(CNC) Computer Numerical Control Machinist Technical Practice Test

CNC Cutting Tool Geometry & Selection 3