Exam Questions And Correct Answers

Ohio CNC Operator Level 1 Practice Exam Questions And Correct Answers (Verified Answers) Plus Rationales 2025|2026 Q&A | Instant Download Pdf

• What does CNC stand for?
• Computer Numerical Control
• Computerized Numerical Control
• Calculated Numerical Control
• Controlled Numerical Calibration

Rationale: CNC machines are automated milling or turning machines

controlled by a computer using numerical data.

• Which axis typically represents left-right movement on a CNC

machine?

• Y-axis
• Z-axis 1 / 4

• X-axis
• W-axis

Rationale: On CNC machines, the X-axis usually represents horizontal

movement left and right.

3. The purpose of a coolant in CNC machining is to:

• Increase friction
• Reduce heat and remove chips
• Harden the cutting tool
• Lubricate the motor

Rationale: Coolant prevents overheating of both the tool and workpiece

and helps flush away chips.

• What is the standard unit for spindle speed in CNC machines?

A. RPM

• Revolutions per minute
• Hz
• M/min

Rationale: Spindle speed refers to how many revolutions per minute the

spindle makes.

• Which G-code is used to move the tool to a specific coordinate at a

controlled feed rate?

A. G00

B. G01 2 / 4

C. G02

D. G03

Rationale: G01 is a linear interpolation code for moving at a controlled

feed rate.

6. G02 is used for:

• Linear movement
• Clockwise circular interpolation
• Counterclockwise circular interpolation
• Rapid positioning

Rationale: G02 commands a clockwise arc movement in CNC machining.

• Which part of the CNC machine holds the cutting tool?
• Chuck
• Spindle
• Bed
• Tailstock

Rationale: The spindle rotates and holds the cutting tool in place.

8. The difference between G00 and G01 is:

• G00 is linear, G01 is circular
• G00 is rapid movement, G01 is controlled feed
• G00 rotates clockwise, G01 counterclockwise
• There is no difference 3 / 4

Rationale: G00 moves the tool rapidly without concern for cutting, while

G01 moves at a feed rate suitable for cutting.

• What is the purpose of a tool offset?
• Speed up spindle rotation
• Adjust for tool length and diameter
• Reduce vibration
• Change coolant flow

Rationale: Tool offsets allow precise compensation for the tool’s actual

physical dimensions.

• Which device measures the actual position of a CNC axis?
• Encoder
• Stepper
• Servo motor
• Linear scale

Rationale: Linear scales provide feedback on the exact position of CNC axes

for precision.

• What does “H” represent in a tool offset?
• Diameter
• Height (length)
• Helix angle
• Hardness

Rationale: H-codes are used in tool offset tables to specify the tool length.

• / 4