CNC Cutting Tools and Tooling 2

Question 1

What does SFM stand for in CNC cutting tool calculations?

Accepted Answer

Surface Feet per Minute

Answer

SFM stands for Surface Feet per Minute, a measure of the cutting speed at the tool's cutting edge relative to the workpiece.

Question 2

Using the formula RPM = (SFM × 3.82) / Diameter, what RPM is needed for a 0.5-inch end mill at 600 SFM?

Accepted Answer

4,584 RPM

Answer

RPM = (600 × 3.82) / 0.5 = 2,292 / 0.5 = 4,584 RPM, which is the required spindle speed for this tool and cutting speed.

Question 3

What is the chip load (feed per tooth) for a 4-flute end mill running at 3,000 RPM with a feed rate of 60 IPM?

Accepted Answer

0.005 inches

Answer

Chip load = Feed Rate / (RPM × Number of Flutes) = 60 / (3,000 × 4) = 60 / 12,000 = 0.005 inches per tooth.

Question 4

What is the primary function of a drill's point angle?

Accepted Answer

To affect how the drill starts and centers itself

Answer

The drill point angle affects how the drill centers itself on entry and how aggressively it cuts — 118° is standard for general use, 135° for harder materials.

Question 5

Which tool type is specifically designed to enlarge and improve the surface finish of an existing hole?

Accepted Answer

Reamer

Answer

A reamer is designed to slightly enlarge a pre-drilled hole while producing a very precise diameter and superior surface finish.

CNC - Cutting Practice Test

CNC - Cutting Practice Test

CNC Cutting Tools and Tooling 2