G03

Machining center, LatheModal, group 01

Circular interpolation, counterclockwise (CCW) / helical interpolation

⌨Format and notes

G17 G03 X_ Y_ R_ (or I_ J_) F_ / lathe: G03 X(U)_ Z(W)_ R_ (or I_ K_) F_

Diagram: G03 arc: direction, center, I/J, R

XYIJRStartEndCenterG03: counterclockwise (CCW)Direction: view the plane fromthe + side of its normal axisG17 (XY): from +ZG18 (ZX): from +YG19 (YZ): from +XI, J: start to center(incremental even in G90)R: arc radius(a full circle can't use R)
The tool travels counterclockwise around the center from start to end (figure is viewed from the +Z side in G17, i.e. from above). Helical interpolation adds a simultaneous linear Z move to this arc. For a lathe (G18), the direction is the same in a drawing with X+ up and Z+ to the right.

📚Sources

The meaning shown agrees in at least two sources (agreement confirmed). Explanations are written in our own words.

  1. Mitsubishi Electric — The Basics of CNC Machining Programming (for Machining center) e-Learning material (PDF) mitsubishielectric.com
  2. Mitsubishi Electric — The Basics of CNC Machining Programming (for Lathe) e-Learning material (PDF, BNP-C8027-688) mitsubishielectric.com
  3. Siemens AG — SINUMERIK 802D sl/840D/840D sl/840Di/840Di sl/810D Programming Manual ISO Milling, 04.2007 Edition (6FC5398-7BP10-0BA0) cache.industry.siemens.com
  4. Haas Automation, Inc. — Mill Operator's Manual – 17 Mill G-Codes (online version) haascnc.com
  5. Haas Automation, Inc. — Lathe Operator's Manual – 16 Lathe G-Codes (online version) haascnc.com
  6. National Institute of Standards and Technology (NIST), USA — The NIST RS274NGC Interpreter – Version 3 (NISTIR 6556, 2000) nvlpubs.nist.gov
  7. Ministry of Health, Labour and Welfare (MHLW), Human Resources Development Bureau, Office of the Councillor for Skills Evaluation — Human resource development manual using the practical exam tasks of the Grade 3 Skilled Worker Test: CNC lathe work (March 2018) waza.mhlw.go.jp