G83 — Deep Hole Peck Drilling Cycle (Full Retract)
G83 fully retracts to the R-plane after each peck, allowing complete chip clearance and coolant access to the cutting zone.
Format (Fanuc / Haas Standard)
G83 X_ Y_ Z_ R_ Q_ F_ ;| Code | Meaning |
|---|---|
| X, Y | Hole position |
| Z | Final depth (from R-plane) |
| R | Retract plane (rapid height) |
| Q | Peck depth per increment |
| F | Feed rate |
Example
G90 G00 G54 X50 Y25 ;
G43 Z10 H01 M08 ;
G99 G83 Z-40 R2 Q8 F120 ;
G80 ;Drills at X50 Y25 to Z-40 in 8 mm pecks, retracting to R2 after each peck.
Haas I-J-K Progressive Peck Option
G83 X_ Y_ Z_ I_ J_ K_ R_ F_ ;| Code | Meaning |
|---|---|
| I | First peck depth (largest) |
| J | Reduction per pass |
| K | Minimum peck depth |
Example: G83 Z-40 I12 J3 K4 R2 F120 — first peck 12 mm, then 9, 6, minimum 4 mm.
G73 — Chip Breaking Cycle (Partial Retract)
G73 retracts a small amount (0.005–0.050 in or 0.1–1.0 mm) after each peck to break chips without fully clearing the hole.
Format
G73 X_ Y_ Z_ R_ Q_ F_ ;| Code | Meaning |
|---|---|
| Q | Incremental peck depth (each advance) |
| d | Retract distance (set by machine parameter, typically ~0.5 mm) |
When to Use G83 vs G73
| Cycle | Retract Behavior | Use Case |
|---|---|---|
| G73 | Small retract (chip break) | Short holes, stringy materials, aluminum |
| G83 | Full retract to R-plane | Deep holes, poor chip evacuation, steel/Inconel |
For deep hole drilling (L/D > 5), G83 is preferred to ensure complete chip clearance.
G98 vs G99 Retract Mode
| Code | Retract Between Holes |
|---|---|
| G98 | To initial Z level (clear parts/fixtures) |
| G99 | To R-plane only (faster, same-part repeat) |
Full Program Example — G83 on Fanuc/Haas
O1000 (DEEP HOLE DRILLING)
N10 T01 M06 ;
N20 G90 G80 G17 G54 ;
N30 G00 X0 Y0 ;
N40 G43 H01 Z50.0 ;
N50 S1500 M03 ;
N60 M08 ;
N70 G99 G83 X25 Y25 Z-60.0 R3.0 Q10.0 F150 ;
N80 X75 Y25 ;
N90 X25 Y75 ;
N100 X75 Y75 ;
N110 G80 G00 Z50.0 ;
N120 M09 ;
N130 M05 ;
N140 M30 ;Peck Strategy Recommendations
| L/D Ratio | q (peck depth) | Retract Mode | Notes |
|---|---|---|---|
| ≤ 3 | Full depth | G73 | Shallow, use chip break |
| 3–5 | 2–3× D | G73 or G83 | Moderate pecking |
| 5–10 | 1–2× D | G83 | Standard deep hole |
| 10–20 | 0.5–1× D | G83 | Reduce peck for chip clearance |
| > 20 | 0.3–0.5× D | G83 + pilot hole | Use dedicated DHD method |
Coolant Considerations in G-Code
For deep hole drilling on machining centers (per VDI 3211):
- M07 / M08: Standard flood coolant — adequate for L/D < 3
- Through-spindle coolant (TSC): Required for L/D > 3. Activate with M41 or M88 depending on machine
- Minimum 40 bar recommended for L/D > 5
- For deeper holes, consider M355 (high-pressure coolant on) if available
Custom Macro Alternative (Advanced)
#1 = -60.0 (Z final depth)
#2 = 2.0 (R-plane)
#3 = 8.0 (Q peck)
#4 = 0.5 (W clearance)
#5 = 150.0 (F feed)
#6 = #2 - #3
G01 Z#6 F2000
G01 Z#1 F#5
G00 Z#2Source: Fanuc programming manuals; Haas programming guide; CNC Training Centre; mfgrobots.