加工如图所示螺纹孔的加工程序（设Z轴开始点距工作表面100mm处，切削深度为20mm）。

　

图6.17 螺纹加工循环

　

①先用G81钻孔

  ％0101

  N10 G91 G00 M03

  N20 C98 G81 X40.0 Y40.0 Z-22.0 R-98.0 F100

  N30 G98 G81 X-120.0 Z-22.0 R-98 L3

  N40 G98 G81 X-120.0 Y50.0 Z-22.0 R-98

  N50 G98 G81 X40.0 Z-22.0 R-98 L3

  N60 G80 X-160.0 Y-90.0 M05

  N70 M02

②再用G84攻螺纹

  ％0102

  N100 G91 G00 M03

  N110 G99 G84 X40.0 Y40.0 Z-27.0 R-93.0 F280

  N120 G99 G84 X40.0 Z-27.0 R93 L3

  N130 G99 G98 X-120.0 Y50.0 Z-27 R-93

  N140 G99 G84 X40.0 Z-27.0 R-93 L3

  N150 G80 Z93.0  N81 X-160.0 Y-90.0 M05

  N160 M02