Exam Questions And Correct Answers

Ohio CNC Operator Level 2 Practice Exam Questions And Correct Answers (Verified Answers) Plus Rationales 2025|2026 Q&A | Instant Download Pdf

• What does G00 code typically command on a CNC machine?
• Feed at programmed feed rate
• Rapid positioning
• Circular interpolation
• Thread cutting

Rationale: G00 is used for rapid, non-cutting moves to position the

tool quickly.

• Which coordinate system is referenced to the machine’s physical zero

point?

• Work offset
• Tool offset
• Machine coordinate system (MCS)
• Local coordinate system 1 / 4

Rationale: MCS is fixed to the machine and used as a reference for all

positions.

• What is the primary function of G01 code?
• Rapid traverse
• Drill cycle
• Linear interpolation at a programmed feed rate
• Peck drilling

Rationale: G01 moves the tool in a straight line at a controlled feed

rate for cutting.

• Which coolant type is typically used for aluminum machining?
• Water-soluble oil
• Straight oil
• Synthetic oil
• Water-based coolant

Rationale: Water-based coolant provides good cooling and chip

evacuation for aluminum.

• What does the “tool offset” compensate for?
• Material hardness
• Tool length and diameter variations
• Machine vibration
• Workholding misalignment

Rationale: Tool offsets ensure the machine compensates for actual

tool size and length. 2 / 4

• Which factor has the greatest effect on tool life?
• Machine weight
• Cutting speed
• Workpiece color
• Coolant color

Rationale: Cutting speed directly affects heat generation and tool

wear.

• What does the G02 command perform?
• Linear movement
• Clockwise circular interpolation
• Counterclockwise circular interpolation
• Drill cycle

Rationale: G02 moves the tool along a clockwise arc in the XY plane.

• Which type of CNC machine is primarily used for turning?
• Milling machine
• Drilling machine
• Lathe
• EDM machine

Rationale: A lathe rotates the workpiece and uses a stationary

cutting tool for turning operations.

• When programming a part in inches, what code is used?

A) G21

B) G20 3 / 4

C) G90

D) G91

Rationale: G20 sets the CNC to inch mode; G21 sets metric mode.

• What does the “fixture offset” compensate for?
• Tool wear
• Machine calibration
• Workpiece location on the table
• Coolant flow

Rationale: Fixture offsets adjust the coordinate system to match the

physical placement of the workpiece.

• What is the purpose of peck drilling cycles?
• Increase spindle speed
• Break chips and reduce heat during deep hole drilling
• Decrease tool diameter
• Polish the hole surface

Rationale: Peck drilling retracts the drill periodically to prevent chip

clogging and overheating.

• Which motion mode is G03 used for?
• Rapid traverse
• Linear feed
• Counterclockwise circular interpolation
• Drilling cycle

Rationale: G03 performs CCW arcs in the XY plane.

• / 4