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G81

Machining centerModal, group 09

Drilling cycle (spot drilling)

⌨Format and notes

G81 X_ Y_ Z_ R_ F_ K_

The simplest drilling: rapid to the R point, feed to Z, rapid back out
R is an absolute position under G90 and a distance from the initial point under G91. The same applies to Z
K (L on some machines) is the repeat count. Combine it with G91 to drill equally spaced holes

Diagram: G81 motion (side view)

Rapid to the R point, then cutting feed from the R point to hole bottom Z. Figure shows G98 (return to initial point); with G99 it stops at the R point and moves to the next hole.

📚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. — 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