Printed from Kezuriba (kezuriba.net/en/nc/g98/)

G98

Machining center, LatheModal, group 10

Canned cycle: return to initial point

⌨On machining centers

G98 G81 X_ Y_ Z_ R_ F_

After drilling, returns to the height before entering the cycle (the initial point) before moving to the next hole. For clearing clamps or steps
If the initial point is lower than the R point, it returns to the R point (NIST)
The default on many machines (Siemens ISO M)

Diagram: Height to move to the next hole after drilling

G98 returns to the initial point (the height before entering the cycle) after drilling and then moves to the next hole. G99 moves at the R point height, which is faster, but collides with a clamp or step in the way.

◎On lathes: Feed per minute (mm/min) (G-code system A)

The same number means something different on lathes (FANUC-type G-code system A). Group 05.

G98 G01 X_ F_ (F is in mm/min)

On lathes, G98/G99 switch the feed unit (equivalent to G94/G95 on machining centers)
On lathes in systems B/C, G98/G99 are the return points of canned cycles (Siemens ISO T, group 11)

≠Differences between controls and machines

The same code can be written or assigned differently depending on the CNC control and the machine builder. Always check your machine’s manual.

Source	Machine	Item	Detail
Haas	Lathe	Group	10
Siemens (ISO dialect)	Lathe	Meaning	In system B: return to initial point in drilling cycles (group 11)

📚Sources

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

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
Haas Automation, Inc. — G-code, M-code, and Setting (per-code explanation pages) haascnc.com
Haas Automation, Inc. — Mill Operator's Manual – 17 Mill G-Codes (online version) haascnc.com
National Institute of Standards and Technology (NIST), USA — The NIST RS274NGC Interpreter – Version 3 (NISTIR 6556, 2000) nvlpubs.nist.gov
Mitsubishi Electric — The Basics of CNC Machining Programming (for Lathe) e-Learning material (PDF, BNP-C8027-688) mitsubishielectric.com
Haas Automation, Inc. — Lathe Operator's Manual – 16 Lathe G-Codes (online version) haascnc.com
Siemens AG — SINUMERIK 802D sl/840D/840D sl/840Di/840Di sl/810D Programming Manual ISO Turning, 04.2007 Edition cache.industry.siemens.com