CNC Canned Cycles Explained: G73, G81, G83, G84, G76 and More

CNC Canned Cycles Explained: G73, G81, G83, G84, G76 and More

Canned cycles in CNC simplify repetitive machining operations like drilling, tapping, boring, and threading. Instead of manually programming each line, a single command handles multi-step actions.

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📦 What Are Canned Cycles?

Canned cycles are predefined sequences in the CNC control that automate common tasks.

Benefits:

• Shorter code
• Faster programming
• Consistent toolpaths
• Easier edits

All canned cycles are typically modal — they stay active until cancelled (usually with G80).

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🔩 Common Canned Cycles and Their Functions

Code	Name	Description
G73	High-speed Peck	For shallow peck drilling
G81	Standard Drilling	Basic drilling to depth
G82	Drilling with Dwell	Drilling with pause at bottom
G83	Deep Hole Peck	Peck drilling with full retract
G84	Tapping	Rigid or floating tap cycle
G85	Boring	Feed-in and feed-out boring
G76	Threading Cycle	Multi-pass threading
G80	Cancel Cycles	Ends active canned cycle

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🛠️ G81 — Standard Drilling Cycle

G81 R2 Z-15 F150

• R: Retract level
• Z: Final depth
• F: Feedrate

This lowers to Z at feedrate, then retracts to R level.

✅ Ideal for basic drilling operations.

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🔁 G83 — Deep Hole Peck Drilling

G83 R2 Z-25 Q5 F100

• Q: Peck depth
• Each peck drills Q deep, then retracts to R to clear chips

Best for deep holes, sticky materials, or chip evacuation.

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⚙️ G73 — High-Speed Peck

G73 R2 Z-10 Q2 F200

• Minimal retraction
• High-speed for shallow holes

Use when you want speed over chip removal.

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⛓️ G84 — Tapping Cycle

G84 R1 Z-15 F75

• For rigid or floating tapping heads
• Requires spindle synchronization
• Feedrate must match thread pitch!

⚠️ Incorrect feed = tap breakage.

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🔁 G76 — Threading Cycle (Lathe)

A multi-pass threading cycle for external/internal threads.

G76 P010060 Q100 R0.05
G76 X20 Z-30 P1020 Q300 F1.5

• P: Depth, finishing passes
• Q: Min depth
• R: Taper
• F: Pitch

Requires precise setup and proper spindle feedback.

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🧭 Canned Cycle Structure

For most G81–G89 style cycles:

G98 G81 X10 Y10 R2 Z-15 F100
G80

• G98: Return to initial point after retract (vs G99 → R-level)
• G80: Cancels the cycle

Use G98 when you want clearance after each hole.

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📘 Drilling Multiple Holes

G98 G81 R2 Z-10 F100
X0 Y0
X20 Y0
X20 Y20
X0 Y20
G80

This drills 4 holes in one block using the same cycle.

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🧠 Tips for Using Canned Cycles

• Always cancel with G80 before rapid moves
• Ensure spindle speed and direction is appropriate
• Use G83 or G73 based on depth and material
• Prefer G98 when clearance is needed above clamps
• For tapping (G84), match feedrate = pitch × RPM

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🚀 Comparison: G81 vs G83 vs G73

Feature	G81	G83	G73
Type	Basic drill	Deep peck drill	High-speed peck
Pecking	No	Yes (with retract)	Yes (no retract)
Use Case	Soft materials	Deep holes	Shallow pecking
Chip Evacuation	Minimal	Excellent	Moderate

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🔄 Looping with Subprograms + Canned Cycles

Combine M98 + canned cycles for large grids of holes.

G81 R2 Z-10 F100
M98 P1000 L4
G80

O1000
X[#100] Y[#101]
#100=[#100+20]
M99

Efficient, parametric drilling automation.

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✅ Summary

Canned cycles are essential building blocks for efficient CNC programming. Whether you’re drilling, tapping, or threading, they reduce complexity while maintaining reliability.

Mastering each canned cycle — G81, G83, G84, and others — empowers CNC programmers to produce safer, cleaner, and faster code with minimum effort and maximum consistency.