Printed from Kezuriba (kezuriba.net/en/nc/g86/)

G86

Machining centerModal, group 09

Boring cycle (spindle stops at the hole bottom, rapid out)

⌨Format and notes

G86 X_ Y_ Z_ R_ F_ K_

Because the spindle is stopped and the tool is pulled out at rapid, the cutting edge may leave a light line on the bore wall. Use G76 if marks are unacceptable

Diagram: G86 motion (side view)

Feeds to the hole bottom, stops the spindle, and rapids out. On retraction the cutting edge may leave a line on the bore. Figure shows G98.

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
NIST	Machining center	Format	G86 … P_ (dwell at hole bottom)

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. — 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