G76

◎On lathes: Multiple thread cutting cycle (compound thread cutting cycle)

The same number means something different on lathes (FANUC-type G-code system A). Group 00.

G76 P_ (m: finishing passes, r: chamfer amount, a: tool nose angle, 2 digits each) Q_ (minimum depth of cut) R_ (finishing allowance);
G76 X(U)_ Z(W)_ R_ (taper amount) P_ (thread height) Q_ (first depth of cut) F_ (lead)

• Two-block format. P in the first line is 6 digits: 2 digits for the number of finishing passes + 2 digits for the chamfer amount + 2 digits for the tool nose angle (e.g. P012060)
• P in the second line is the thread height and Q is the first depth of cut (both radius values). P, Q, and R have different meanings in the first and second lines
• Single-flank cutting with a constant cutting amount per pass, so the load on the tool is light (Siemens ISO T)
• F is the lead, not the pitch (for multi-start threads, pitch × number of starts)
• The Siemens ISO T example writes X/Z/P/Q in the second line in least input increments without a decimal point (e.g. P3680 Q1800). Check the machine's decimal point handling